Relationship between quantity of silver stained nucleolar organizer region associated proteins (Ag-NORs) and growth rate suppression of breast cancer cell lines after interferon-gamma and 4-hydroxy-tamoxifen treatment

Effects of human platelet lysate on the growth of cultured human corneal endothelial cells

Human platelet lysate (hPL) as a replacement for foetal bovine serum (FBS) in culturing human corneal endothelium is an emerging area of interest, although there are limited studies evaluating the quality of the hPL being used. Our study aimed to evaluate variations between sources of hPL and to explore the efficacy of hPL (with and without heparin) as a replacement for FBS in culturing human corneal endothelial cells in vitro. Immortalized human corneal endothelial cells (B4G12) and primary human corneal endothelial cells (PHCEnCs, n = 11 donors, age from 36 to 85 years old) were cultured with 5% hPL or FBS. A full characterisation of the effects of hPL and FBS on cell growth was conducted using IncuCyte Zoom (percentage cell confluence and population doubling time, PDT) to analyse cell proliferation. AlamarBlue assays were used to measure cell viability. The concentration of fibrinogen, PDGF, hEGF, VEGF and bFGF in two sources of hPL were analyzed by Enzyme-linked immunosorbent assay. Expression and localization of Na+/K+-ATPase, ZO-1 and CD166 on PHCEnCs and B4G12 cells were assessed with immunofluorescence and immunoblotting. Our results showed that a significant difference in fibrinogen, hEGF and VEGF concentrations was found between two sources of hPL. Heparin impaired the positive effect of hPL on cell growth. PDT and alamarBlue showed that hPL significantly increased proliferation and viability of PHCEnCs in two of three donors, and immunostaining indicated that hPL increased ZO-1 and CD166 expression but not Na+/K+-ATPase on PHCEnCs. In addition, heterogeneities on immunopositivity of Na+/K+-ATPase and ZO-1 and morphology were found on PHCEnCs derived from an individual donor cultured with hPL medium. In conclusion, hPL showed positive effect on primary corneal endothelial cell growth, and maintenance of their cellular characteristics compared to FBS. hPL can be considered as a supplement to replace FBS in PHCEnC culture. However, the variation observed between different hPL sources suggests that a standard quality control monitoring system such as storage time and a minimal concentration of growth factors may need to be established.

DNA methylation of nuclear receptor genes--possible role in malignancy

The members of the nuclear receptor superfamily are known to mediate a wide array of basic biological processes, such as regulation of cell growth and differentiation, and induction of apoptosis. In several human malignancies, this central control function of nuclear receptors is disturbed, which seems to play an important role in tumor development and progression. Many nuclear receptor genes have been reported to be downregulated in malignancies; however, only a few mutations, gene arrangements, deletions or similar genetic changes have been shown to occur in these tumors. During the last decade, increasing attention has been directed towards epigenetic mechanisms of gene regulation such as DNA methylation. Many nuclear receptor genes can be silenced through aberrant methylation in tumors; epigenetic silencing, therefore, represents an additional mechanism that modifies expression of key genes during carcinogenesis. This review will give insights into the role of DNA methylation in the silencing of nuclear receptor genes and its involvement in human malignancies.

Demonstration of silver-stained nucleolar organizer region associated proteins (AgNORs) after wet autoclave pretreatment in breast carcinoma: correlation to tumor stage and long-term survival

Argyrophilic nucleolar organizer region associated proteins (AgNORs) are known to reflect cellular and nucleolar activity. Due to a novel staining procedure, which substantially improves visualisation of AgNORs on formalin-fixed and paraffin-embedded material, AgNORs can be reliably demonstrated as true substructures of the nucleoli. The aim of the present study was to apply a standardized morphometric AgNOR quantification on a large series of breast carcinomas with regard to its prognostic relevance. AgNOR quantity was evaluated on archival tumor tissues of 115 adenocarcinomas of the breast treated with the wet autoclave method prior to standardized silver-staining and morphometric analysis. AgNOR parameters were correlated to prognostic features (steroid hormonal receptor status, tumor type, tumor size, histological grading, pTNM, and UICC stage) carrying out both univariate and multivariate survival analyses. AgNOR number and area were proven to be statistically significantly related (Pearson correlation coefficient: 0.67, Bonferroni adjusted P = 0.0001). Almost all AgNOR parameters, in particular CV (coefficient of variation) of corrected area (delta-area) and CV of number, were statistically significantly correlated to estrogen and progesterone receptor status as well as histological grading of tumors. Increased AgNOR parameters were statistically significantly associated with early tumor relapse and cancer related death. Univariate and multivariate analysis by means of Cox regression revealed independent prognostic significance for CV of delta-area and number of AgNORs. Various AgNOR parameters (CV of number, CV of delta-area, CV of area, mean delta-area, and mean area of AgNORs per nucleus) determined on wet autoclave pre-treated formalin-fixed and paraffin-embedded breast cancer tissues are statistically highly significantly associated with the prognostic outcome, independently predicting tumor-free and overall survival.

Quantification of C-ERB-B2 gene amplification in breast cancer cells using fluorescence in situ hybridization and digital image analysis

Fluorescence in situ hybridization (FISH) allows detection of the intercellular heterogeneity of C-ERB-B2 gene amplification in uncultured breast cancer cells. Nevertheless, because high levels of amplification result in coalescence of signals, direct microscopy quantification is restricted to cells wih low levels of amplification or with dispersed signals. A methodology of digital image analysis, using surface and grey-level FISH signals as parameters that permit a rapid, objective, and accurate estimation of gene copy number, is presented. This procedure is independent of the signal overlapping and results in a more accurate quantification and characterization of tumor cell heterogeneity.

Standardized staining and analysis of argyrophilic nucleolar organizer region associated proteins (AgNORs) in radically resected colorectal adenocarcinoma--correlation with tumour stage and long-term survival

Quantification of silver-stained nucleolar organizer region associated proteins (AgNORs) was introduced in histopathology as a marker of cellular and nucleolar activity. However, due to the poor staining quality obtained on routinely processed archival material, the method yielded controversial and sometimes non-reproducible results. The recent introduction of wet autoclave pretreatment has reliably improved AgNOR staining quality on routinely formalin-fixed and paraffin-embedded tissues. In the present study, 92 routinely processed colorectal carcinomas were investigated, applying this novel staining technique. Subsequent standardized morphometric analysis revealed, irrespective of common tumour staging or grading classifications, a statistically highly significant correlation between AgNOR parameters and clinical course. The usefulness of standardized AgNOR parameters for the independent prediction of patient survival was proven by uni- and multivariate analysis.