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.

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.

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.

[Morphometric parameters of nuclei in EBV-positive and EBV-negative Hodgkin's lymphoma]. / Morfometrické parametry jader nádorových bunek EBV pozitivních a EBV negativních Hodgkinských lymfomu.

Five morphometric parameters of nuclei of EBV-positive and EBV-negative Hodgkin's lymphoma cells were assessed for length, width, area, circumference, and circularity. For the measurement of the nuclei of the tumor cells (Hodgkin, Reed-Sternberg cells) the system of image analysis "Lucie" was used. In comparison with EBV-positive Reed-Sternberg cells, the nuclei of the EBV-negative Reed-Sternberg cells had significantly larger circumference, area and width. The nuclei of the Hodgkin cells in EBV-negative Hodgkin's lymphomas had significantly larger width and circularity. The authors assume that the altered morphometric parameters are related to a latent EBV infection.

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.

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.

[Biological characteristics of multiple myeloma]. / Nekteré biologické charakteristiky mnohotného myelomu.

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.

Apoptosis of malignant cells in Hodgkin's disease is related to expression of the cdk inhibitor p27KIP1.

Previous results from B-cell chronic lymphocytic leukaemia suggest that expression of p27KIP1 might be important in protection from apoptosis. Given the relevance of apoptosis to the pathogenesis of Hodgkin's disease (HD), it was decided to examine the expression of p27KIP1 in relation to apoptosis in these lesions. Paraffin-wax sections from a total of 65 histologically confirmed HD tumours were used to derive apoptotic index (AI) and DNA fragmentation index (DFI) scores, which were compared with the expression of various cell-cycle-regulating proteins, including p27KIP1 (p27), p21WAF1/CIP1 (p21) and cyclin D1, and with Epstein-Barr virus (EBV) status. The DFI was measured by TdT-mediated dUTP-FITC nick end-labelling (TUNEL), and the AI by conventional morphology. Cells showing the typical morphology of apoptosis, together with those resembling so-called 'mummified' Hodgkin/Reed-Sternberg (HRS) cells, were included in AI measurements. Increasing numbers of p27-positive HRS cells were associated with lower levels of apoptosis in these cells, as indicated by significantly lower AI and DFI scores. There was a trend towards poorer survival in those patients with the highest numbers of p27-positive HRS cells and with lower AI and DFI scores, but these differences were not statistically significant. p21-positive HRS cells were significantly more frequent in those cases with lower AI scores. A similar trend was observed for p21 and DFI, although this relationship was not statistically significant. There was also a trend towards higher levels of cyclin D1 protein in HD cases with high AI and DFI values. A tendency for increasing numbers of p27-positive and p21-positive HRS cells in EBV-positive cases was noted, but this relationship was not statistically significant. EBV status did not correlate with either AI or DFI scores. The results of this study suggest that p27, and possibly also p21, may be involved in protection from apoptosis in HD.

[Assessment of metastatic potential of pulmonary carcinoma]. / Odhad metastatického potenciálu plicního karcinomu.

The authors evaluated in a group of 25 patients after radical lung resection on account of a non-small cell carcinoma the correlation between tumour grading, invasion into lymphatic and blood vessels, proliferation markers (Ki-67, PCNA), ploidy, cell polymorphism and mitotic cell activity of the lung tumour and the lymphogenic or haematogenic metastatizing proved before or during surgery. From the investigation patients after induction chemotherapy were eliminated. It was of interest that the great majority of investigated parameters was positive or elevated in patients with lymphogenic or haematogenic metastases. Conversely in patients where the majority of these parameters was negative on the day of the operation, no metastases were detected. In the group of patients where the investigated indicators were positive and no metastasis was found, similarly as in both previous sub-groups, the author will continue to follow-up the following: recurrence, median survival and five-year survival. From the assembled parameters a table was prepared stratifying the risk of metastases.