[Biomarkers in the detection of minimal systemic dissemination in lung cancer patients]

INTRODUCTION

Minimal systemic disease (MSD) means the presence of circulating or disseminated tumour cells in mesenchymal compartments of a patientts' body (lymphatic nodes, blood or bone marrow). The aim of our pilot study was to identify sensitive and specific markers for MSD detection in 50 lung cancer patients, who underwent curative surgery in the I. Department of Surgery, Faculty of Medicine and Dentistry, Palacky University and Faculty Hospital Olomouc in 2009 and 2010.

MATERIAL AND METHODS

Absolute gene expression of carcinoembryonic antigen (CEA), epidermal growth factor receptor (EGFR1), lung-specific X protein (LUNX) and hepatocyte growth factor receptor (c-met) was determined in peripheral blood, bone marrow and pulmonary blood of 50 lung cancer patients using real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR).

RESULTS

(1) The LUNX marker is specific and sensitive for MSD detection in lung cancer patients. (2) The CEA positivity for MSD in the bone marrow correlated significantly with histopathological grading (GI-GIII). (3) Higher expression of CEA and c-met was found in pulmonary blood of patients with hilar or mediastinal lymphadenopathy. (4) Higher expression of MSD markers (CEA in bone marrow, c-met in peripheral blood and LUNX in pulmonary blood) correlated with higher pTNM classification.

CONCLUSION

Minimal systemic disease detection in lung cancer patients is technically feasible using sufficiently sensitive and specific markers for RT-PCR. Minimal systemic disease detection can be used to guide further systemic treatment. This theory must be validated in a larger group of patients and correlated with clinical data, especially with survival data.

The mechanism of action of the tumour suppressor gene PTEN

Intracellular levels of phosphorylation are regulated by the coordinated action of protein kinases and phosphatases. Disregulation of this balance can lead to cellular transformation. Here we review knowledge of the mechanisms of one protein phosphatase, the tumour suppressor PTEN/MMAC/TEP 1 apropos its role in tumorigenesis and signal transduction. PTEN plays an important role in the phosphatidyl-inositol-3-kinase (PI3-K) pathway by catalyzing degradation of phosphatidylinositol-(3,4,5)-triphosphate generated by PI3-K. This inhibits downstream targets mainly protein kinase B (PKB/Akt), cell survival and proliferation. PTEN contributes to cell cycle regulation by blockade of cells entering the S phase of the cell cycle, and by upregulation of p27(Kip1) which is recruited into the cyclin E/cdk2 complex. PTEN also modulates cell migration and motility by regulation of the extracellular signal-related kinase - mitogen activated protein kinase (ERK-MAPK) pathway and by dephosphorylation of focal adhesion kinase (FAK). We also emphasize the increasingly important role that PTEN has from an evolutionary point of view. A number of PTEN functions have been elucidated but more information is needed for utilization in clinical application and potential cancer therapy.

The stem cell marker CD133 (Prominin-1) is expressed in various human glandular epithelia

Human prominin-1 (CD133) is expressed by various stem and progenitor cells originating from diverse sources. In addition to stem cells, its mouse ortholog is expressed in a broad range of adult epithelial cells, where it is selectively concentrated in their apical domain. The lack of detection of prominin-1 in adult human epithelia might be explained, at least in part, by the specificity of the widely used AC133 antibody, which recognizes an epitope that seems dependent on glycosylation. Here we decided to re-examine its expression in adult human tissues, particularly in glandular epithelia, using a novel monoclonal antibody (80B258) generated against the human prominin-1 polypeptide. In examined tissues, we observed 80B258 immunoreactivity at the apical or apicolateral membranes of polarized cells. For instance, we found expression in secretory serous and mucous cells as well as intercalated ducts of the large salivary and lacrimal glands. In sweat glands including the gland of Moll, 80B258 immunoreactivity was found in the secretory (eccrine and apocrine glands) and duct (eccrine glands) portion. In the liver, 80B258 immunoreactivity was identified in the canals of Hering, bile ductules, and small interlobular bile ducts. In the uterus, we detected 80B258 immunoreactivity in endometrial and cervical glands. Together these data show that the overall expression of human prominin-1 is beyond the rare primitive cells, and it seems to be a general marker of apical or apicolateral membrane of glandular epithelia. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.

The status and role of ErbB receptors in human cancer

Changes in the expression of cellular receptors contribute to the progression of many types of solid tumors. In this review, we focus on the normal role of ErbB receptors as signal transducers and their contribution to carcinogenesis when there are abnormalities in ErbB signaling due to the overactivity of the receptors or the overexpression of ligands, which can lead to developmental defects and have been associated with many types of cancers.

Anticancer and antiproliferative activity of natural brassinosteroids

Brassinosteroids (BRs) are steroid plant hormones that are essential for many plant growth and developmental processes, including cell expansion, vascular differentiation and stress responses. Up to now the inhibitory effects of BRs on cell division of mammalian cells are unknown. To determine basic anticancer structure-activity relationships of natural BRs on human cells, several normal and cancer cell lines have been used. Several of the tested BRs were found to have high cytotoxic activity. Therefore, in our next series of experiments, we tested the effects of the most promising and readily available BR analogues with interesting anticancer properties, 28-homocastasterone (1) and 24-epibrassinolide (2), on the viability, proliferation, and cycling of hormone-sensitive/insensitive (MCF-7/MDA-MB-468) breast and (LNCaP/DU-145) prostate cancer cell lines to determine whether the discovered cytotoxic activity of BRs could be, at least partially, related to brassinosteroid-nuclear receptor interactions. Both BRs inhibited cell growth in a dose-dependent manner in the cancer cell lines. Flow cytometry analysis showed that BR treatment arrested MCF-7, MDA-MB-468 and LNCaP cells in G(1) phase of the cell cycle and induced apoptosis in MDA-MB-468, LNCaP, and slightly in the DU-145 cells. Our results provide the first evidence that natural BRs can inhibit the growth, at micromolar concentrations, of several human cancer cell lines without affecting the growth of normal cells. Therefore, these plant hormones are promising leads for potential anticancer drugs.

PML and TRF2 protein expression in hereditary and sporadic colon cancer

The PML (promyelocytic leukemia) protein is concentrated in the PML nuclear bodies. In human cell lines and tumors maintaining their telomeres by alternative lengthening (ALT), the PML protein is colocalized with TRF2 and several other proteins in the so called ALT-associated PML bodies. The aim of this study was to determine if there is any difference in PML protein expression between tumors with stable microsatellites (MSS) and those with high-frequency microsatellite instability (MSI-H), if PML protein expression might be a prognostic factor and if MSI-H tumors more frequently use alternative lengthening of telomeres measured by the presence of ALT-associated PML bodies. Eighty colorectal cancer samples (32 MSI-H and 48 MSS) and 8 human tumor cell lines (Saos-2, U2OS, DU145, LNCaP, U87, HeLa, MCF7 and T98G) were included into the study. Double-colour immunofluorescence staining was used. Downregulation of PML protein expression was found in 7 of 32 (22%) MSI-H and 11 of 48 (23%) MSS tumors (p=0.520). There was no correlation between PML expression and age, histological typing, localization of the tumor in colon, TNM classification, disease-free and overall survival. The Saos-2 and U2OS (ALT using cell lines) and the MCF7 (active telomerase) cell line were characterized by the presence of ALT-associated PML bodies; no such bodies were detected in the DU145, LNCaP, U87, HeLa and T98G cell lines (active telomerase); accumulation of TRF2 was absent or much weaker in these cell lines compared to Saos-2 or U2OS. Accumulation of the TRF2 protein was detected in 16 of 80 (20%) tumors and PML and TRF2 colocalization in 2 MSI-H tumors (6%). In conclusion, the PML protein was downregulated in approximately 20% of tumors; there was no difference between MSS and MSI-H tumors. PML protein expression does not seem to be a prognostic factor.

PML protein expression in hereditary and sporadic breast cancer

The PML protein is concentrated in the PML nuclear bodies. Downregulation of the PML protein has been described in various types of cancer and is in accordance with the fact that dysqualification of tumor suppressive functions of the PML protein might promote cancer development. Various differences have been described between sporadic breast cancer and that associated with BRCA1 and BRCA2 gene mutations. Expression of the PML protein has not been studied yet. The aim of this study was to determine if there is any difference in PML protein expression in breast cancer of BRCA1 and BRCA2 gene mutation carriers compared to sporadic breast cancer and if the PML protein can be used as a prognostic marker. There were 47 breast cancer samples included, 14 and 10 from BRCA1 and BRCA2 germline mutation carriers, respectively, and 23 from patients without a BRCA1/BRCA2 germline mutation. Immunofluorescence staining was used. Downregulation of PML protein expression was found in 2 of 14 (14%), 3 of 10 (30%) and 15 of 47 (31%) cases of breast cancer samples from BRCA1, BRCA2 and no BRCA1/BRCA2 mutation carriers, respectively (p(BRCA1) = 0.019; p(BRCA2) = 0.111). There was no correlation between PML protein expression and age, histological types, estrogen and progesterone receptor, c-erbB-2 and PCNA expression, TNM classification, disease-free and overall survival. In conclusion, the PML protein is downregulated in approximately 30% of breast cancers cases. Downregulation of PML protein expression was significantly less frequent in BRCA1 mutation carriers compared to sporadic cases. No correlation was found between PML protein expression and any of the other clinical and laboratory characteristics.

[Bone marrow angiogenesis in patients with multiple myeloma as a marker of biological behaviour]

Angiogenesis, the creation of new blood vessels from preexisting vascular nets, plays a major role in the development, progression and dissemination of solid malignant tumors. Research over the last few years has shown a correlation of angiogenesis and the biological behaviour of haematologic malignancies. This study focused on the relation of vasoformation, stage of differentiation of tumour plasmocytes and type of bone marrow infiltration in patients with multiple myeloma (MM) prior to treatment. We evaluated trephine biopsy samples from 55 patients for microvessel density in 1 mm2 field by monoclonal antibody anti CD34. Angiogenesis correlated with the type of infiltration and with stage of morphological differentiation. It was highest in the nodular type of infiltration with a low level of differentiation, and lowest in grade 1 differentiation with an interstitial type of infiltration.

[Proliferative and apoptotic markers in prostate carcinoma in relation to androgen receptor]

Prostate carcinoma, one of the most frequent male malignancies, is in certain stages of its development significantly influenced by androgens. Therefore, we carried out a retrospective study on a set of 130 patients with nongeneralized, localized prostate carcinoma (stage T1-T2, PSA up to 25 ng/ml). We determined immunohistochemically the expression of proliferation markers PCNA and Ki67, Bax, p53, Bcl-2, p21waf1, p27kiP1 and compared them with the expression of the androgen receptor (AR). Multivariation statistical analysis of the results using the chi-square test with Pearson's correction and variability analysis using the SPSS 8.0 software program showed a strong correlation of the PCNA and Ki67 proliferation markers with the expression of hormonal dependence and apoptosis markers. The expression of PCNA correlated strongly with p27 kip1 and Bax, while the expression of Ki67 correlated most strongly with p27 kip1 and Bcl-2. The expression of p27 kip1 correlated with the expression of androgen receptor, PCNA, Ki67 as well as Bcl-2. None of the observed markers correlated significantly with Gleason's score. We did not find substantial significant relation between the observed markers and the expression of p53 and p21 waf1. The results indicate a significant role of the expression of p27 kip1 protein in regulating proliferative activity and hormonal responsiveness in the initial stage of prostate carcinoma.

Immunohistochemical analysis of the biological potential of odontogenic keratocysts

BACKGROUND

The aim of this study was to analyse the usefulness of detecting important apoptosis and proliferation markers in assessing the biological potential of odontogenic keratocysts (OKC) and thus selecting the optimal diagnostic algorithm for these lesions.

METHODS

Indirect immunohistochemistry and relevant statistical methods were used for analysis of formalin-fixed and paraffin-embedded samples from 98 patients.

RESULTS

Nevoid basal cell carcinoma syndrome (NBCCS) keratocysts were characterized by higher expression of Bcl-2, p27Kip1 and c-erbB-2 as well as by lower proliferative activity measured by Ki-67 in basal cell epithelium and by a lower inflammatory response in comparison with sporadic keratocysts. Dentigerous, radicular and non-specified odontogenic cysts differed from both NBCCS and sporadic keratocysts in a wide spectrum of apoptosis and/or cell cycle-related protein expressions, higher proliferation in the basal cell layer, and vice versa, lower proliferation in the suprabasal cell layer.

CONCLUSIONS

The NBCCS keratocysts have a different immunophenotype from sporadic keratocysts and both types are distinguishable from dentigerous, radicular and non-specified odontogenic cysts. These findings confirm the separate biological potential of these lesions and the results of the immunohistochemical analysis have diagnostic and prognostic implications.

Analysis of ERBB2 and TOP2A gene status using fluorescence in situ hybridization versus immunohistochemistry in localized breast cancer

The aim of our study was to assess the ERBB2 and TOP2A gene status in breast carcinoma tissue using fluorescence in situ hybridization (FISH) and to compare their amplification with immunohistochemistry assay (IHC) of the ERBB2, resp. topoisomerase IIalpha proteins. TOP2A status is important in tailored treatment as topoisomerase IIalpha is the molecular target for topoisomerase IIalpha inhibitors. This study was conducted to determine whether the methods are equivalent in their assessment of TOP2A status and to correlate the genetic findings with basic tumor and disease characteristics. Locus specific ERBB2, TOP2A genes and chromosome 17 centromeres (CEP17) probes were hybridized to 72 formalin-fixed paraffin-embedded (FFPE) tissue samples from patients with non-metastatic breast carcinoma (M0). The ERBB2, TOP2A and CEP17 signals were counted and gene numbers per nucleus or per CEP17 were calculated, respectively. Sections were also stained with commercial polyclonal antibody (HercepTestTM), anti-topoisomerase IIalpha monoclonal antibody (clone SWT3D1) and scored for the presence of membrane/nuclear staining. ERBB2 amplification was found in 20.3%, ERBB2 and TOP2A co-amplification was detected in 14.5% of cases. Deletion of the ERBB2/TOP2A gene was found in 1.4/2.8% of sections, respectively. Concordance of FISH and IHC techniques in the evaluation of ERBB2 and TOP2A status was found in 88.4% and 66.7%, respectively. The low concordance of FISH versus IHC in the evaluation of TOP2A status was mainly due to the presence of TOP2A amplified tumors in IHC negative or weakly positive specimens. Topoisomerase IIalpha expression was increased in bigger tumors, although direct correlation with tumor grading was not found. ERBB2 amplification was found in more aggressive breast cancers with grades 2 and 3, respectively. Interestingly, chromosome 17 polysomy was more frequently observed among older women (>55 years), suffering usually from less aggressive disease. Our results confirm the high concordance of the ERBB2 and TOP2A gene co-amplification in breast carcinoma. Differences between FISH and IHC in the case of ERBB2 gene status were found only in IHC 2+ sections as reported in the literature. However, our study points to the importance of FISH examination of TOP2A gene status in all tumors with ERBB2 amplification.

[Immunohistochemical study of the apoptotic and proliferative mechanisms in the intestinal mucosa during coeliac disease]

Mechanisms leading to morphological changes of the small intestine during coeliac disease are not yet completely recognized, however, two main processes have been suggested recently: remodelling of mucosa by matrix metalloproteinases, and mucosal atrophy by apoptosis. The aim of this study was to analyze the expression of proteins regulating apoptosis and some markers of proliferation in the mucosa of the small intestine of children with active (ACD) and latent form (LCD) of coeliac disease (CD). Intestinal biopsies of 43 children with ACD and LCD were analyzed by standard indirect immunohistochemical technique for Fas, Fas ligand (Fas-L), tissue transglutaminase (tTG), Bcl-2, Bid, glutathione S-transferase (GST), CAS 3, CAS 8, PARP, Ki-67, Topoisomerase IIa, PCNA expression. We found significantly lower numbers of Fas-expressing enterocytes in ACD patients than in LCD patients and controls. The number of Fas-positive mucosal lymphocytes was decreased in ACD when compared with LCD. Fas-L expression in enterocytes and mucosal lymphocytes was higher in ACD and LCD compared to controls. We found significantly more Bcl-2 negative lymphocytes in ACD than in LCD and controls. Bid expression in enterocytes was higher in LCD compared to ACD and controls. In intraepithelial lymphocytes, there was higher Bid expression in LCD than in ACD and controls compared to expression in mucosal lymphocytes, where was found higher number of positive cells in controls than in ACD and LCD. Expression of CAS 8 in mucosal lymphocytes was significantly higher in ACD compared to LCD. The expression of tTG in extracellular matrix and basal lamina was significantly higher in LCD and ACD when compared to controls. Expression of tTG was higher in the group of ACD and LCD in the enterocytes and in the lymphocytes. Our findings showed that Fas/Fas-L, Bcl-2, and CAS 8 may be involved in modulation of apoptosis during CD. Increased apoptotic elimination of IEL in LCD can partially explain preservation of the normal villous architecture. Increased tTG expression may be an early sign of increased apoptosis or may be related to its role in CD pathogenesis.

DIFFERENTIATION OF TUMOURS OF DUCTAL AND LOBULAR ORIGIN: I. PROTEOMICS OF INVASIVE DUCTAL AND LOBULAR BREAST CARCINOMAS

The vast majority of invasive breast tumors are ductal and lobular breast carcinomas. Despite the many similarities, some clinical follow-up data and the patterns of metastases suggest that these histological subtypes of breast cancer are biologically distinct. Few papers, however, describe immunohistochemical markers useful for differentiation of these carcinomas. Many investigations suggest that E cadherin protein expression is lost in lobular but not in ductal carcinoma. The absence of E-CD, as a partial loss of epithelial differentiation, may account for the extended spread of lobular carcinoma in situ and the peculiar diffuse invasion mode of invasive lobular carcinoma. Some investigations report the significance of E-CD associated proteins alpha-, beta-, gamma-catenin expression, as well as the usefulness of cytokeratins 5, 6, 8, 7 and thrombospondin in differentiating histological types of breast invasive carcinomas. Several reports have suggested the possibility that invasive ductal and lobular cancers differ with respect to expression of antigens involved in proliferation and cell cycle regulation. It has been shown that vascular endothelial growth factor expression, also the expression of maspin, a tumour suppressor gene product, is higher in ductal, than in lobular carcinoma. Expression of NKX3.1, a member of the NK-class of homeodomain, is highly restricted and is found primarily in lobular carcinoma. Some histological and immunohistochemical characteristics of pleomorphic lobular carcinoma are also discussed.

Differentiation of tumours of ductal and lobular origin: II. Genomics of invasive ductal and lobular breast carcinomas

Breast cancer is considered to be a multifactorial disorder caused by both genetic and non-genetic factors. Different histological types of breast cancer differ in response to treatment and may have a divergent clinical course. Breast tissue is heterogeneous, with components of epithelial, mesenchymal, endothelial and lymphopoietic derivation. The genetic heterogeneity of invasive breast cancer is reflected by the wide spectrum of histological types and differentiation grades. Nevertheless, the influences of these cell types on the tumour's total pattern of gene expression can be estimated analytically. Microarrays permit total tissue analysis and provide a stable molecular portrait of tumours. Some investigations suggest differences in the gene expression profiling for ductal and lobular carcinomas. It has been reported that inactivating mutations of the E-cadherin gene are very frequent in infiltrating lobular breast carcinomas. Other than altered expression of E-cadherin, little is known about the underlying biology that distinguishes ductal and lobular tumour subtypes. However, about 8 genes have been identified differentially which are expressed in lobular and ductal cancers: E-CD, survivin, cathepsin B, TPI1, SPRY1, SCYA14, TFAP2B, and thrombospondin 4, osteopontin, HLA-G, and CHC1. Expression profiling of breast cancers can be used diagnostically to distinguish individual histologic subclassifications and may guide the selection of target therapeutics. However, future approaches will need to include methods for high throughput clinical validation and the ability to analyze microscopic samples.

Nestin expression by newly formed human blood vessels

Nestin is a type VI intermediate filament protein originally described in neural stem cells. Here we report that immature endothelial cells generated in the course of angiogenesis express nestin. Endothelial cells of embryonic capillaries destined to vascularize growing organs also express this intermediate filament protein. Whereas nestin was sporadically expressed in mature adult human endothelial cells sporadically express nestin, this protein was consistently expressed in adult angiogenic vasculature. Nestin expression was also detected in capillaries of the corpus luteum, which replenishes itself by angiogenesis. Nestin-immunoreactive vessels were also observed in the infarcted hearts where transient ischemia triggered regeneration accompanied with neovascularization of the myocardium. Nestinpositive endothelial cells lined vessels nourishing solid growing tumors, including melanoblastomas and glioblastomas. Our data provide definitive evidence that endothelial precursors express the neural stem cell marker nestin and that this protein participates in formation of the cytoskeleton of newly formed endothelial cells. Because nestin expression was recognized under all conditions of vascular development, nestin represents a novel and reliable marker of neovascularization.

Microarray analysis of bicalutamide action on telomerase activity, p53 pathway and viability of prostate carcinoma cell lines

Bicalutamide is a non-steroidal anti-androgen commonly used in the treatment of prostate carcinoma. We analysed the transcriptional response to bicalutamide treatment with the aim of explaining the inhibition of telomerase in the androgen-sensitive cell line LNCaP and the effects of bicalutamide on the androgen-insensitive cell line DU145. Cells treated with 80 muM bicalutamide in steroid-depleted medium for 1 day were analysed in duplicate by Affymetrix Human Genome Focus Arrays. Response to bicalutamide in LNCaP cells was represented by downregulation of androgen-regulated genes, activation of the p53 pathway and inhibition of telomerase, which was associated with downregulation of v-myc avian myelocytomatosis viral oncogene homologue (MYC) and telomerase reverse transcriptase subunit. In DU145 cells we observed the influence of cell density on bicalutamide effectivity such that highly confluent cells showed lesser sensitivity than low confluent ones. In conclusion, we provide an explanation for telomerase inhibition after androgen receptor blockade in LNCaP cells and we also report activation of the p53 pathway in LNCaP cells and in-vitro sensitivity to bicalutamide of low confluent androgen-insensitive DU145 cells. These findings might have implications for both experimental and clinical research into prostate cancer. In particular, activation of the p53 pathway after treatment with 80 microM bicalutamide could justify usage of bicalutamide dosages higher than 150 mg daily in androgen-sensitive carcinoma therapy.

Nestin as a diagnostic and prognostic marker: immunohistochemical analysis of its expression in different tumours

The designation NESTIN refers to a member of the family of intermediate filaments and comes from the fact that this protein is expressed mainly in neuroepithelial stem cells. However, nestin is not expressed in mature elements and terminal cell differentiation is associated with loss of immunoreactivity to this protein. Therefore, immunohistochemical assessment of nestin expression might be useful to differentiate between mature and immature elements. The aim of this study was to analyse nestin expression in various tumours of neuroectodermal and vascular origin and to determine whether its detection has practical relevance. The results indicate that the immunohistochemical detection of nestin expression could be useful in astrocytomas and malignant melanomas, where it could be used as an auxiliary indicator of dedifferentiation and progression. Because of the weak and heterogeneous expression of nestin in neurinomas, phaeochromocytomas, and carcinoids, nestin detection in these lesions is of little practical use.

Comparison of protective effect of protein and DNA vaccines hsp90 in murine model of systemic candidiasis

Preventive vaccination by a hsp90-expressing DNA vaccine and recombinant hsp90 protein vaccine, both derived from the Candida albicans hsp90 using BALB-c mouse model of systemic candidiasis, was performed. Hsp90 mRNA was cloned from a clinical isolate of C. albicans, converted to cDNA and cloned into vaccination plasmid pVAX1. Two methods of DNA application were tested: intramuscular (i.m.) and intradermal (i.d.) injection. Recombinant protein was applied by i.d. injection with Freund's adjuvant; the control groups received PBS or Freund's adjuvant only. Mice were vaccinated and after 19 d re-vaccinated. After 3 weeks, the mice were challenged with the live C. albicans in a dose of 5 x 10(6) CFU per mouse. After the challenge, the mice vaccinated i.d. with DNA vaccine survived for 39 and 64% longer compared to those receiving Freund's adjuvant and/or PBS, respectively. The i.m. application of the DNA vaccine did not provide any significant protectivity. The serum level of anti-candida-hsp90 serum IgG antibodies correlated with the survival rate in both i.d. protein and DNA vaccination approaches. We stressed the importance of specific humoral immunity in the mouse model of systemic candidiasis.

Expression of the hMLH1 and hMSH2 proteins in normal tissues: relationship to cancer predisposition in hereditary non-polyposis colon cancer

The majority of tumours in patients with hereditary non-polyposis colon cancer (HNPCC) occur in large intestine and endometrium; also, other tissues are at increased risk. We studied expression of hMLH1 and hMSH2 proteins in 148 normal samples of various tissues from non-HNPCC patients and in 14 normal colon tissues from HNPCC patients. Immunohistochemical technique was used. Intensity of nuclear staining, percentage of stained cells and H-scores were calculated. Tissues were divided into groups. Groups A, B and C included tissues with increased risk of cancer in HNPCC A) stomach, small and large bowel; (B) endometrium; (C) ovary, ureter, urinary bladder, kidney and liver. Group D tissues were without increased risk. Expression of the proteins was significantly higher in groups A, B and C compared with group D (P<0.0001, P=0.0004 for hMSH2 in C versus D). The expression was highest in testis. In colons of HNPCC patients, expression of the mutated gene product was significantly lower than in non-HNPCC patients. In conclusion, hMLH1/hMSH2 protein expression is constitutively higher in certain cell types of certain tissues, including the majority of tissues that are at increased risk of cancer in HNPCC. However, association of strong hMLH1/hMSH2 expression with cancer risk is not strictly valid.

Solitary intracranial metastasis of follicular carcinoma of the thyroid gland clinically mimicking a meningioma

We describe a rare case of solitary metastasis of follicular carcinoma of the thyroid gland into the petroclival region in a 58-year-old woman. The metastasis was the first and only manifestation of the disease. The histology of the tumor, differential diagnosis and clinical course are discussed. In a few similar cases described so far the tumor was always a well or moderately differentiated follicular carcinoma located in the petroclival region. As in this presentation, these cases also clinically mimic a meningioma. The differential diagnosis includes adenoma of the thyroid gland and thyroid gland dystopia. We demonstrated the primary focus of carcinoma within the thyroid after its detailed examination initiated by our finding. The clinical outcome of such rare cases is usually excellent, much better than in metastases of papillary carcinoma into the brain.

Synergic effects of the cyclin-dependent kinase (CDK) inhibitor olomoucine and androgen-antagonist bicalutamide on prostatic cancer cell lines

Currently, mechanisms leading to both apoptosis induction and the development of hormone-independence of prostate carcinoma cells are intensively studied. Attention is also given to the possibility of restoring cell sensitivity to hormone-antagonists. The present study focuses on the effect of the combined synthetic cyclin-dependent kinase [CDK] inhibitor, olomoucine and the antiandrogen bicalutamide on hormone-insensitive (DU-145) and hormone-sensitive (LNCaP) prostate cancer cell lines. In both cell lines reduction in cell viability was significantly higher when olomoucine and bicalutamide were applied in combination when compared to separate application of both these drugs. The setting of optimal concentrations for both substances was important for the final effect on both cell lines. The proliferation arrest was accompanied by a decrease in cyclin D1 expression and the activation of p21Waf1/Cip1 and p27Kip1 pathways in both cell lines. Contrary to the previously described effect of 200 microM olomoucine, weak AR induction after treatment with effective concentrations of olomoucine was not seen in the hormone- insensitive cell line DU-145. The related reaction of DU-145 and LNCaP cell lines to treatment with combined olomoucine and bicalutamide likely provides evidence that the inhibitory effect of bicalutamide may not only be associated with its antiandrogenic properties. The tested substances probably influence different regulatory pathways and these have co-operative impact on the cell cycle outcome. Understanding antitumor and antihormone actions of both agents is essential for the development of novel therapeutic schemes integrating substances with different action. Our results show that the combination of synthetic CDK inhibitors and hormone- antagonists may be one of a number of possible alternatives.

Immunohistochemical detection of the hMLH1 and hMSH2 proteins in hereditary non-polyposis colon cancer and sporadic colon cancer

Defects in DNA mismatch repair system are involved in carcinogenesis of sporadic and inherited human cancers. We assessed the feasibility of using immunohistochemistry to detect tumors with DNA mismatch repair deficiency. We analyzed 81 samples (74 colon cancers (CC), 1 colon dysplasia and 6 extracolonic cancers) for hMLH1 and hMSH2 protein expression, microsatellite instability (MSI) and/or mutational analysis. A meta-analysis of the published data on immunohistochemistry of hMLH1/hMSH2 proteins was performed. Sensitivity and specificity of the method was calculated. Twenty four of 29 tumors from hMLH1/hMSH2 mutation carriers and 10 of 13 sporadic high frequency MSI tumors lost one of the proteins. None of the 42 tumors with stable microsatellites or low frequency MSI lost the proteins. Based on literature review of 49 publications on colorectal cancer, hMLH1 immunohistochemistry was able to detect 136 of 154 tumors from hMLH1 germline mutation carriers (the sensitivity of 88.3% [95%CI, 85.8-90.8%]), hMSH2 immunohistochemistry detected 99 of 109 tumors from hMSH2 mutation carriers (the sensitivity of 90.8% [95%CI, 88.5-93.1%]), and hMLH1/hMSH2 immunohistochemistry identified 1262 of 1382 tumors with high-frequency microsatellite instability not correlated with mutational analysis (the sensitivity of 91.3% [95%CI, 90.4-92.2%]). The specificity of the method was 99.4% (95%CI, 99.2-99.6%). In conclusion, immunohistochemistry of hMLH1 and hMSH2 proteins is a useful method to predict the presence of mismatch repair deficiency, although its sensitivity is lower than that of MSI analysis.

Proto-oncogene c-myc in uterine cervix carcinogenesis

The biological behaviour of precancerous and early stages of uterine cervix carcinoma is not always easily predictable. It is important therefore to identify new biological markers which could more reliably predict the evolution of the disease or provide important therapeutic targets. To establish the role of the proto-oncogene c-myc in uterine cervix tumorigenesis, we examined 96 tissue samples of different degrees of cervical intraepithelial neoplasia (CIN1-CIN 3), in situ (CIS) or invasive squamous cell carcinoma (ISCC) and control cases. Indirect immunohistochemical techniques were used to detect the c-myc expression. Significantly higher levels of Myc protein were found in keratinocytes of high-grade dysplasias in comparison to low-grade dysplasias and control cases. There was no difference between low-grade CIN and a control group of patients. The same significant changes between above mentioned groups were seen in surrounding stromal cells (fibrocytes, fibroblasts, some endothelial cells and lymphocytes). We confirm that expression of c-Myc protein is increased not only in uterine cervix cancer but also in the premalignant lesions. Problem for discussion seems there for whether increased Myc expression in stromal cells might create a more tumor promoting microenvironment which may support the growth and proliferation of transformed cells.

Pathobiology of androgenetic alopecia

Human hair morphogenesis is a dynamic process caused by the remodelling of the skin. Hair growth is cyclic in mammals consisting of three distinct stages: an active stage (anagen), a regressive stage (catagen), and a resting stage (telogen). One disorder in this process is gradual balding of the scalp called androgenetic alopecia. Little is known about the cell biological or molecular mechanisms involved and thus very little treatment is currently available. In this review we focus on the most significant parameters affecting hair growth which participate in baldness.

The significance of key regulators of apoptosis in the development and prognosis of prostate carcinoma. II. Products of suppressor genes Rb and PTEN, CDKI, Fas

The molecular basis for the transition of carcinoma of the prostate from androgen-dependent to androgen-independent growth is largely unknown. Currently for example, it is not clear whether the androgen-independent phenotype is a result of selection of a subgroup of genetically distinct prostate tumour cells which are already hormone-resistant or a genetic adaptation of prostate tumour cells to the hormone therapy itself. It has also been established that prostate tumour transformation is a result of homeostatic control defects, a line of thinking directed toward elucidating the apoptotic profile of prostate tumour cells that may be important in determining prognosis, response to therapy and illness progression. Main consideration in this part of rewiev is given to the role of tumour suppressor genes pRb and PTEN and also the natural inhibitors of cyclin dependent kinases - proteins p21(Waf1/Cip1) and p27(Kip1). Attention is also given to the role of FAS-mediated pathways in apoptosis induction.

The significance of key regulators of apoptosis in the development and prognosis of prostate carcinoma. I. Proteins of the Bcl-2 family and protein p53

The molecular basis for the transition of carcinoma of the prostate from androgen-dependent to androgen-independent growth is largely unknown. Currently for example, it is not clear whether the androgen-independent phenotype is a result of selection of a subgroup of genetically distinct prostate tumour cells which are already hormone-resistant or a genetic adaptation of prostate tumour cells to the hormone therapy itself. It has also been established that prostate tumour transformation is a result of homeostatic control defects, a line of thinking directed toward elucidating the apoptotic profile of prostate tumour cells that may be important in determining prognosis, response to therapy and illness progression. Main consideration in this part of rewiev is given to the role of Bcl-2 and members of the Bcl-2 family, and tumour suppressor gene p53.

The significance of key regulators of apoptosis in the development and prognosis of prostate carcinoma. II. Products of suppressor genes Rb and PTEN, CDKI, Fas

The molecular basis for the transition of carcinoma of the prostate from androgen-dependent to androgen-independent growth is largely unknown. Currently for example, it is not clear whether the androgen-independent phenotype is a result of selection of a subgroup of genetically distinct prostate tumour cells which are already hormone-resistant or a genetic adaptation of prostate tumour cells to the hormone therapy itself. It has also been established that prostate tumour transformation is a result of homeostatic control defects, a line of thinking directed toward elucidating the apoptotic profile of prostate tumour cells that may be important in determining prognosis, response to therapy and illness progression. Main consideration in this part of rewiev is given to the role of tumour suppressor genes pRb and PTEN and also the natural inhibitors of cyclin dependent kinases - proteins p21(Waf1/Cip1) and p27(Kip1). Attention is also given to the role of FAS-mediated pathways in apoptosis induction.

The mechanism of action of the tumour suppressor gene PTEN

Intracellular levels of phosphorylation are regulated by the coordinated action of protein kinases and phosphatases. Disregulation of this balance can lead to cellular transformation. Here we review knowledge of the mechanisms of one protein phosphatase, the tumour suppressor PTEN/MMAC/TEP 1 apropos its role in tumorigenesis and signal transduction. PTEN plays an important role in the phosphatidyl-inositol-3-kinase (PI3-K) pathway by catalyzing degradation of phosphatidylinositol-(3,4,5)-triphosphate generated by PI3-K. This inhibits downstream targets mainly protein kinase B (PKB/Akt), cell survival and proliferation. PTEN contributes to cell cycle regulation by blockade of cells entering the S phase of the cell cycle, and by upregulation of p27(Kip1) which is recruited into the cyclin E/cdk2 complex. PTEN also modulates cell migration and motility by regulation of the extracellular signal-related kinase - mitogen activated protein kinase (ERK-MAPK) pathway and by dephosphorylation of focal adhesion kinase (FAK). We also emphasize the increasingly important role that PTEN has from an evolutionary point of view. A number of PTEN functions have been elucidated but more information is needed for utilization in clinical application and potential cancer therapy.

[Diagnosis of lymphoproliferative diseases from bone marrow biopsies]

The cytological, histological and immunophenotypical markers of lymphoproliferative diseases are evaluated in the collection of 950 trepanobiopsies, and correlated with types of extramedullary malignant lymphoma. The diagnostic significance of tumor infiltrates topography and basic rules of the differential diagnoses of malignant lymphomas in the bone marrow biopsies are discussed.

Immunohistochemical study of the apoptotic mechanisms in the intestinal mucosa during children's coeliac disease

Mechanisms leading to morphological changes of the small intestine during coeliac disease (CD) are not yet completely recognized; however, two main processes have been suggested recently: remodeling of mucosa by matrix metalloproteinases, and mucosal atrophy by apoptosis. The aim of this study was analysis of the expression of proteins regulating apoptosis in the small intestine of children with active CD (ACD) and potential CD (PCD). Jejunal biopsies of 43 children with PCD and untreated ACD and 21 control samples were analyzed by means of standard indirect immunohistochemical technique for Fas, Fas ligand (Fas-L), tissue transglutaminase (tTG), Bcl-2, and glutathione S-transferase (GST) expression. We found significantly lower numbers of Fas-expressing enterocytes in the ACD patients than in PCD patients and controls. Similarly, the number of Fas-positive mucosal lymphocytes was decreased in ACD when compared with PCD. The number of Fas-L- and tTG-expressing enterocytes and mucosal lymphocytes was higher in both PCD and ACD. On the other hand, the number of Bcl-2-positive mucosal lymphocytes in PCD as well as ACD was significantly lower. The expression of tTG in extracellular matrix was significantly higher in PCD and ACD when compared with controls. Our results showed that Fas and/or Fas-L, Bcl-2, and tTG may be involved in apoptotic pathways leading to mucosal atrophy in children with CD. tTG changes are in agreement with the presumed role of this protein in the pathogenesis of CD.

[What is the real importance of evaluating the expression of c-erbB-2 (HER-2/neu) in carcinoma of the breast and prostate? (A short review)]

This minireview covers the key data on biology and clinical implications of the c-erbB-2 oncogene in breast and prostate cancer. The aim was to provide basic information to practically oriented pathologists in order to make a reasonable application of methods for c-erbB-2 overexpression or amplification analysis. The clinical interpretation of c-erbB-2 abnormalities should reflect the complexity of c-erbB-2 mediated regulatory pathway and explain why tumours with overexpression/amplification of c-erbB-2 very often do not respond to therapy using Herceptin.

Peroxisome proliferator-activated receptors (PPARs) in health and disease

Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of steroid-thyroid-retinoid nuclear receptors. PPARs are transcription factors activated by specific ligands and play an important role during cell signalling. Intensive study of PPARs during recent years has revealed their importance in both normal physiology and in the pathology of various tissues. They participate in the regulation of lipid metabolism, inflammation and the development of atherosclerosis or diabetes. They also play a role in the regulation of growth and differentiation of cancer. It has been suggested that PPAR ligands may have potent anticancer effects and therefore may serve as potential anticancer drugs. In this review we focus on a role of PPARs in breast cancer and in glial tumors of the brain.

Nuclear receptors in early hormone refractory prostate cancer and their relationship to apoptosis-related proteins

The expression of several genes involved in apoptosis and cell cycle control can be regulated by steroid hormones and related agents via their nuclear receptors. Members of the bcl-2 gene family participate in the regulation of apoptosis in a diverse range of cell types and are implicated in the development of hormone refractory prostate cancer and resistance to anti-cancer therapy. The aim of this study, therefore, was to examine the expression of several nuclear receptors in relation to the expression of apoptosis and cell cycle related proteins in a series of patients with early hormone refractory prostate cancer. Analysis of protein expression revealed only a weak association between Bcl-2 and AR. Bax positivity and p27Kip1 expression were significantly more frequent in the AR-positive tumors, whereas RXRbeta expression was more frequently observed in the AR-negative group. The expression of AR, Bax and p27Kip1 was inversely related, and the expression of RXRbeta directly related, to Gleason pattern status. These results suggest that the immunophenotype of early hormone refractory prostate cancer may be different to that seen in more advanced stage disease. Androgen withdrawal therapy employing anti-androgens may elicit different signalling pathways that may be dependent on ARstatus and ARsensitivity.

Synthetic inhibitors of CDKs induce different responses in androgen sensitive and androgen insensitive prostatic cancer cell lines

AIMS

Because of the high prevalence of prostatic cancer and the limitations of its treatment, enormous effort has been put into the development of new therapeutic modalities. One potential tool is the use of cyclin dependent kinase (CDK) inhibitors, which are based on the trisubstituted derivatives of purine. The aim of this study was to analyse alterations of the regulatory pathways in both androgen sensitive and androgen insensitive prostatic cancer cell lines (LNCaP and DU-145, respectively) after blockage of the cell cycle by the synthetic CDK inhibitors, olomoucine and bohemine.

METHODS

The effects of olomoucine and bohemine were studied on the following parameters: (1) cell proliferation, by measurement of DNA content; (2) viability, by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and/or XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) test; and (3) the expression of p53, pRB, Bcl-2, Bax, p16, p21, p27, cyclins A, B, D1, E, p34(cdc2), and the androgen receptor (AR), by western blot analysis.

RESULTS

Both olomoucine and bohemine were potent inhibitors of growth and viability; however, bohemine was two to three times more effective than olomoucine. The sensitivity of LNCaP cells to both agents was significantly higher. After treatment, both cell lines revealed quite different spectra of protein expression.

CONCLUSIONS

These results indicate the existence of specific cell cycle regulating pathways in both cell lines, which may be associated with both p53 and AR status. CDK inhibitors exhibited valuable secondary effects on the expression of numerous regulators and thus may modulate the responsiveness of tumour cells to treatment, including treatment with hormone antagonists.

Expression of c-erbB-2 in node negative breast cancer does not correlate with estrogen receptor status, predictors of hormone responsiveness, or PCNA expression

The aim of this study was to analyse the relationships between the expression of c-erbB-2, estrogen receptor (ER), progesterone receptor (PR), Bcl-2 and PCNA in node negative breast cancer. Expression of these markers was determined by HercepTest, by immunohistochemistry and quantified by morphometry in the group of 125 selected breast carcinoma patients with broad spectrum of histological types and grades. Multivariate statistical analysis revealed only relationships between ER/PR, ER/Bcl-2, ER/grade and ER/age. There was not found any significant relationship between c-erbB-2 expression and any other immunohistochemical marker, apocrine metaplasia, histological type or patient characteristics. The same result was found in complete group of tumors as well as in individual groups divided according to histological type. These results indicate that in node negative breast tumors, c-erbB-2 expression does not correlate inversely with hormone receptor status and hormone responsiveness like previously reported metastasising breast cancer and that the prognostic significance of c-erbB-2 expression in these tumors is not clear.

The effects of natural ligands of hormone receptors and their antagonists on telomerase activity in the androgen sensitive prostatic cancer cell line LNCaP

The effects of the 17beta-estradiol, dihydrotestosterone and hormone antagonists tamoxifen and bicalutamide on telomerase activity and expression of cell cycle related proteins in the androgen-sensitive prostatic cancer cell line LNCaP were studied. The cell line was grown in RPMI supplemented with 2.5% charcoal-stripped FBS for 72 hr. The IC(50) of tamoxifen and bicalutamide and the optimal stimulatory concentrations of 17beta-estradiol and dihydrotestosterone were determined by means of the cell-viability assay, the activity of telomerase was measured by the telomere repeat amplification protocol (TRAP) and the expression of proteins was analysed by the Western blot technique. 17beta-estradiol stimulated cell growth more effectively than dihydrotestosterone whereas hormone antagonists tamoxifen and bicalutamide caused a significant decrease in cell viability. The treatment of cells by a combination of low doses of 17 beta-estradiol and dihydrotestosterone stimulated cells stronger than treatment by a single hormone. Only 17beta-estradiol, in concentration of 10nM, increased strongly the expression of p21(Waf1/Cip1) and increased slightly telomerase activity in the LNCaP cells. 50 microM of bicalutamide down-regulated the levels of the androgen receptor, the proliferating cell nuclear antigen and telomerase activity, and up-regulated the expression of p27(Kip1). We hereby describe the first observation of the influence of bicalutamide on telomerase activity and a positive correlation between the effect of 17beta-estradiol and the induction of both the endogenous cyclin-dependent kinase inhibitor, p21(Waf1/Cip1), and telomerase activity in a prostatic cancer cell line LNCaP. These findings can shed a new light on the steroid-signaling pathway in prostate cancer cells.

Androgen sensitivity related proteins in hormone-sensitive and hormone-insensitive prostate cancer cell lines treated by androgen antagonist bicalutamide

Members of the bcl-2 gene family and endogenous inhibitors of cyclin-dependent kinases participate in the regulation of apoptosis and cell cycle in a diverse range of cell types and are implicated in the development of hormone refractory prostate cancer and resistance to anti-cancer therapy. The expression of several of these genes can be regulated by steroid hormones and related agents via their nuclear receptors. However, insufficient information considering the protein expression after the treatment by hormone antagonists is available. The aim of this study was to evaluate the expression of anti- and pro-apoptotic proteins, (Bcl-2, Bax), and to correlate this with the appearance of some nuclear receptors and cell cycle related proteins in androgen sensitive and androgen insensitive prostate cancer cell lines, LNCaP and DU-145, after the treatment by androgen antagonist bicalutamide. Our results revealed that androgen receptor (AR) expression in LNCaP cells decreased, however in DU-145 cells AR slightly increased following anti-androgen treatment. The same agent stimulated expression of p21Waf1/Cip5 and p27Kip1 in LNCaP, as well as in DU-145 cell lines. Bcl-2 level increased slightly in LNCaP cells and, in DU-145 cells was almost undetectable. Bax expression was not changed in LNCaP but significantly decreased in DU-145 cells. Similarly, retinoid X receptor beta (RXRbeta) level was significantly down regulated after 24 hours in DU-145 and also in LNCaP cells after 72 hours. These results confirm that androgen withdrawal therapy employing anti-androgens may elicit different signalling pathways in various types of prostate cancer that may be dependent on AR status and AR sensitivity.

DNA ploidy correlates with grade, proliferation and clinical outcome but not with presence of human oncogenic HPVs or expression of Bcl-2 in preneoplastic and neoplastic lesions of the uterine cervix

The aim of this study was to analyse whether DNA ploidy correlates with proliferative activity as measured by PCNA expression, presence of oncogenic human papillomaviruses (HPVs), histological grade, expression of antiapoptotic protein Bcl-2 and clinical outcome in a cohort of 57 preneoplastic and neoplastic lesions of the uterine cervix. The samples were analysed using computer image cytomorphometry of Feulgen stained sections, standard indirect immunohistochemistry and hybridisation of HPV DNA in situ. The ploidy data were found to be significantly different between low/high grade preneoplasia and invasive carcinoma. Significant positive relationships were also found between DNA content and proliferation of lesions, and DNA content and clinical behavior of the lesions. Nevertheless, no relationship between DNA ploidy and HPV/Bcl-2 status was established.

Apoptosis, analysed by means of lamin B detection, correlates with grade of astroglial tumours but not with p27Kip1/retinoblastoma protein expression

The aim of our study was to correlate apoptosis, assessed by means of lamin B degradation, with grade of tumour and immunohistochemical expression of p27Kip1 and retinoblastoma protein (pRB) in a series of 32 low-grade astrocytomas (LGA) and 43 high-grade astrocytomas (HGA). Determination and analysis of lamin B expression was achieved stereologically with the use of computerised interactive image analysis. The average stereological surface density of the lamin-positive nuclear surface of cells showing evidence of lamin degradation cells was 13.80 mm2/mm3 in LGA and 21.02 mm2/mm3 in HGA. The average range of immunopositivity of p27 and pRB expression was 2.85 and 2.10, respectively, in LGA and 1.80 and 0.88, respectively, in HGA. The rate of apoptosis indirectly correlated with the expression of both p27 and pRB but was not fully significant (P < or = 0.09). Our findings suggest that there may be a loss of function of main cell-cycle regulators and increased uncontrolled cell death in addition to increased cell proliferation in high-grade astrocytomas. Moreover, we believe that the detection of lamin B degradation in astroglial tumours can be an alternative, precise and convenient assay for the detection of a defined set of apoptotic cells. However, before being applied more generally, comparative research should be done on different methods of quantifying apoptosis, with the intent of finding the difference between biologically different methods. Such studies would also be able to find the method associated with the strongest prognostic power.

[Applied molecular pathology in oncology]

In the past decades in molecular biotechnology marked advances were made which led to the development of a special branch of pathology and according to some concepts an independent discipline, molecular pathology. This discipline deals with investigations of processes associated with the genesis and development of diseases at the nucleic acid level, proteins coded by these nucleic acids and their signal pathways. To this end molecular-biological techniques are used and the results are put into context with diagnostic and therapeutic procedures of other medical disciplines. It provides extremely valuable information for clinical therapy, in particular of patients with oncological diseases. In the submitted paper a review of some methods used in molecular pathology is given which may be applied in oncological practice. At present some of them are already integrated into common therapeutic protocols. Despite the apparent high cost of new molecular diagnostic methods this will in the long run lead to a reduction of costs spent on less sensitive, less effective and less specific tests as well as to a reduction of unnecessary examinations and to much more successful treatment.

Prognostic factors in astrocytomas: relationship of p53, MDM-2, BCL-2 and PCNA immunohistochemical expression to tumor grade and overall patient survival

The immunohistochemically detected expression of p53, BCL-2, MDM-2 and PCNA proteins in samples of tumor tissues of 42 patients with astrocytomas or glioblastoma multiforme was statistically compared to degree of malignancy and overall survival. We found relation between p53 protein expression and survival in the high grade astrocytomas group (more cases of p53 immunonegative tumors with longer survival), and significantly higher BCL-2 protein expression as well as significantly higher MDM-2 protein expression in the group of low grade astrocytomas. PCNA protein expression showed any relation to tumor grade or survival. Despite the rather small number of samples these results support the hypothesis that MDM-2 protein may be a potent regulator of functional p53, expressed in low grade astrocytoma only.

Immunohistochemical analysis of the functional status of estrogen receptor cascade in breast cancer

Hormone receptor expression in human breast cancer cells does not always reflect tumor response to therapy. Thus, relations between hormone receptor status and other parameters need further examination. The aim of this study was to test the ability of estrogen receptors (ER) to induce progesterone receptor (PR) synthesis as well as to test their role in the regulation of cell proliferation. Measurement of the relation between expressions of ER and the estrogen receptor related protein p29 (ERRP) was a further goal. The results show that some hormone receptor phenotypes are closely related to tumor proliferative activity: in the ER-group, especially ER-PR-phenotype, proliferative activity shows no obvious relationship to phenotype status, suggesting that proliferation in this group probably is not under estrogen control, while in the ER+ group, PR expression was related to reduced proliferation. There was no clear association between ERRP and nuclear ER but the highest ERRP expression was most closely related to ER negative (ER-) or slightly positive (ER +/-) hormone receptor statuses. Tumors with these phenotypes are known to have a poorer prognosis. The conclusion drawn is that simultaneous estimation of proliferative activity, ERRP p29 expression and a comparison with ER/PR hormone receptor phenotype, could provide pathologist with a valuable tool for predicting hormone response and prognosis in breast cancer patients.

The expression of apoptosis-related proteins and the apoptotic rate in glial tumors of the brain

Modern molecular biology methods allow a more precise analysis of the biological characteristics of tumors and, consequently, a more precise treatment plan. The determination of apoptotic rate and expression of apoptosis-related proteins belong among the important prognostic/diagnostic markers in many tumors. The validity of these factors had not yet been sufficiently analyzed in astroglial tumors. The aim of this work was therefore to study mutual relationships between apoptotic rate, expression of apoptosis-regulating proteins and some clinical and histopathological data. The TUNEL method was used for the determination of apoptosis in 44 astroglial tumor specimens. The percentage of TUNEL positive cells was expressed by the TUNEL index (TI). The TI data was compared with the immunohistochemically detected expression of proteins involved in apoptosis (BCL-2, FAS, FAS-L, and caspase 1), with grading, age, proliferative activity (assessed by PCNA expression analysis) and overall survival of patients. The statistical evaluation of results was done by two-way sample analysis of variance. We have demonstrated significantly higher values of both TI and expression of FAS-L and caspase 1 in low grade tumors, which were characterized by a longer survival, lower average age and a lower expression of PCNA. FAS-L expression correlated significantly with the expression of the caspase 1. No significant difference was found between the expression of BCL-2 and FAS. These results suggest that the determination of TI in astroglial tumors may be an important prognostic marker. The expression of FAS-L and caspase 1 in low grade astroglial tumors could indicate the increased readiness to apoptosis via the FAS/FAS-L cascade.

Expression of Bcl-2 in dysplastic and neoplastic cervical lesions in relation to cell proliferation and HPV infection

Expression of the bcl-2 gene has been shown to effectively confer resistance to programmed cell death in a variety of tumors. The bcl-2 proto-oncogene is involved in the development of human follicular lymphomas and also in a number of solid tumors such as carcinomas of prostate, breast, lung and GIT. The present study was designed to analyze the role of Bcl-2 expression in cervical intraepithelial squamous neoplasias (CIN) and cervical invasive carcinomas. Special attention was given to the association of Bcl-2 expression with the grade of the lesion, proliferative activity (expression of nuclear antigen of proliferative cells - PCNA) and human papillomavirus (HPV) DNA positivity. We examined tissue samples obtained from 86 women with varying degrees of cervical disease. Bcl-2 and PCNA were investigated using immunohistochemical staining and detection of HPV DNA was performed by hybridization in situ. Increased Bcl-2 expression was observed in advanced degrees of dysplasia and in carcinomas. We found a strong association between the presence of Bcl-2 in pathological epithelium with both the degree of dysplasia and the proliferative activity. We also observed a significant correlation between the amount of Bcl-2 positive lymphocytes infiltrating the lesions and the degree of disease. We, therefore, suggest that Bcl-2 expression in these lymphocytes may influence the antiviral or antitumor immune response. On the other hand we did not detect any significant correlation between the Bcl-2 oncoprotein and the presence of HPV. These results indicate that Bcl-2 may play an important role in the development of cervical cancer.

[Papillomaviruses and human tumors]

The report summarizes the main results obtained in the course of our research project. The results of immunological and epidemiological studies provide further proofs that human papillomaviruses (HPV) are the etiological agents in cervical neoplasia. In addition, they raise hopes that immunological methods may be utilized in diagnostics of cervical cancer and for monitoring the clinical course of this disease in the near future. Since the etiological relationship between HPV and cervical carcinoma seems to be proven beyond reasonable doubt, the development of prophylactic and therapeutic vaccines has become the dominant of the contemporary HPV reseach. For studying immune reactions against HPV-induced tumours we developed a model of HPV16-transformed rodent cells.

[Biological characteristics of multiple myeloma]

On a series of thirty trephine bone marrow biopsies from patients with multiple myeloma, the authors evaluated expression of markers of cell proliferation or of its blockade (Ki-67, PCNA, topoisomerase IIa, cyclin D-1, AgNOR, and p27kip1) and markers indicating multidrug resistance (P-170 and Bcl-2). Expression of Ki-67 and of topoisomerase IIa was unfrequent. Marked positivity of PCNA was expressed in about one third of cases, negative staining was exceptional. No expression of cyclin D-1 was noted. Positivity of p27kip1 was frequent. P-170 was demonstrated in a small number of cases, Bcl-2 was strongly positive in most cases. The results characterise multiple myeloma as a tumour with low proliferation rate and, simultaneously, with high resistance to apoptosis.

Relation of Bcl-2 expression to androgen receptor, p21WAF1/CIP1, and cyclin D1 status in prostate cancer

BACKGROUND

There is currently no effective treatment for recurrent hormone refractory carcinomas of the prostate gland. An understanding of the underlying mechanisms responsible for the progression of these lesions is likely to be important for the development of new therapeutic approaches. Recently, it has been suggested that the transition to a hormone independent state is accompanied by increased proliferation and bcl-2 gene expression, as well as by a decreased apoptotic state.

AIM

To investigate the possible role of Bcl-2 and other cell cycle regulating proteins in the development of prostatic tumours.

METHODS

Immunohistochemistry was used to study the relation between the expression of Bcl-2 and the androgen receptor, as well as p21WAF1/CIP1 (p21), and cyclin D1 status, in a series of 89 prostate cancer samples taken before androgen withdrawal treatment.

RESULTS

Androgen receptor negative tumours expressed significantly higher amounts of Bcl-2 than those prostate carcinomas with low/medium androgen receptor values. However, in tumours expressing the highest amounts of androgen receptor, Bcl-2 expression was also high. A significant positive relation between Bcl-2 and p21 expression, as well as an inverse relation between Bcl-2 and cyclin D1 expression, was noted. Androgen receptor positive samples also expressed significantly higher amounts of cyclin D1.

CONCLUSIONS

These results suggest that p21 and cyclin D1 expression in prostatic cancer might be modulated by Bcl-2 and by androgens and in turn this could be relevant to the progression of prostatic cancer.