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Erika Marton

Publications and source records attributed to Erika Marton.

7 recordsLinked to original sources
PubMed2003

Interleukin 1 system and sex steroid receptor expression in human breast cancer: interleukin 1alpha protein secretion is correlated with malignant phenotype.

PURPOSE: The interleukin 1 (IL-1) system plays an important role in human pathology and is involved in the local control of malignant disease. However, little is known about its expression in breast cancer and its correlation with prognostic parameters such as receptor status and grading. EXPERIMENTAL DESIGN: The expression of IL-1alpha and other IL-1 family members was analyzed by reverse transcription-PCR, ELISA, and immunohistochemistry in breast cancer cell lines, tumor-derived fibroblasts, and breast cancer tissue biopsies and compared with sex steroid receptor status and grading. RESULTS: In breast cancer cell lines, IL-1alpha and -beta gene expression was present in the phenotypically most malignant cell lines, whereas estrogen receptor (ER) alpha and progesterone receptor mRNA expression was confined to lines that exhibit a rather benign phenotype. Only the highly malignant receptor-negative tumor cell line MDA MB 231 expressed IL-1alpha protein, and none of the cell lines secreted IL-1beta. Biopsies from breast cancer tissue expressed various amounts of IL-1alpha, IL-1beta, and IL-1 receptor antagonist mRNA, but consistently high levels of IL-1tIR. IL-1alpha protein expression was detected in tumor cells and/or adjacent stroma in 88%, and epithelial protein expression was correlated with both poor differentiation (P = 0.002; r = 0.469) and decreasing epithelial ERalpha expression (P = 0.004; r = -0.387). Furthermore, stromal IL-1alpha was predominant in areas with low or absent ERalpha protein expression in neighboring tumor epithelium (P = 0.001; r = -0.457). CONCLUSION: We have demonstrated the presence of a functional IL-1 system in breast cancer and found that IL-1alpha is inversely correlated with local sex steroid receptor expression. We hypothesize that the unphysiological expression of IL-1alpha in less differentiated and ERalpha-negative tumors might contribute to their local invasiveness and malignant behavior.

Breast Neoplasms↗
PubMed2003

Expression of sex steroid receptors and their co-factors in normal and malignant breast tissue: AIB1 is a carcinoma-specific co-activator.

The differential expression pattern of estrogen receptor alpha (ER-alpha), estrogen receptor beta (ER-beta) and their co-activator/co-repressor proteins is thought to modulate estrogenic action and to be present already during the early stages of tumorigenesis. It has therefore been postulated that certain co-activator and co-repressor proteins contribute to the development of breast cancer. There are some reports providing information on gene amplification and mRNA over-expression of certain co-factors in breast cancer, but to date there is only limited knowledge about their respective protein expressions. The aim of this study was to examine the expression of four steroid receptor co-activators (steroid receptor co-activator 1 (SRC-1), transcription intermediary factor 2 (TIF 2), protein 300 kDa/CREB binding protein (p300/CBP), amplified in breast cancer 1 (AIB1)), and of the co-repressor nuclear receptor co-repressor (NCoR), in malignant breast tissues and in matching normal breast biopsies of the same individuals. Protein expression was analyzed by immunohistochemistry and was compared to prognostic parameters such as lymph node involvement, tumor grading and receptor status. All members of the co-regulatory protein family were detected in both, benign and matching malignant tissue samples, except for AIB1, which was found to be expressed exclusively in malignant epithelium. AIB1 was preferentially present in carcinomas with high tumor grade (r = 0.48, p = 0.014), and was co-expressed with p300/CBP (r = 0.54, p = 0.006). TIF 2 correlated significantly to nodal status (r = 0.46, p = 0.025). Furthermore, protein levels of ER-beta p300/CBP and AIB1 were higher in invasive ductal carcinomas than in normal mammary tissue. The tumoral ER-alpha protein expression was significantly correlated with that of PgR (r = 0.61, p = 0.001) and NCoR (r = 0.4, p = 0.043), whereas ER-beta expression was associated with SRC-1 (r = 0.68, p < or = .001), TIF 2 (r = 0.64, p = 0.001) and NCoR (r = 0.48, p = 0.014) protein levels in malignant specimens. In our hands, 20% of ER-beta positive tumors did not express ER-alpha protein, thereby suggesting that a substantial fraction of ER-beta positive tumors is falsely considered to be 'estrogen receptor negative' if only ER-alpha specific antibodies are employed in the histological assessment of the ER status.

Breast↗
PubMed2003

Oct-4-expressing cells in human amniotic fluid: a new source for stem cell research?

BACKGROUND: It is the hope of investigators and patients alike that in future the isolation of pluripotent human stem cells will allow the establishment of therapeutic concepts for a wide variety of diseases. A major aim in this respect is the identification of new sources for pluripotent stem cells. Oct-4 is a marker for pluripotent human stem cells so far known to be expressed in embryonal carcinoma cells, embryonic stem cells and embryonic germ cells. METHODS: Cells from human amniotic fluid samples were analysed for mRNA expression of Oct-4, stem cell factor, vimentin and alkaline phosphatase via RT-PCR. Oct-4 protein expression was investigated by Western blot analysis and immunocytochemistry. Oct-4-positive cells were also analysed for the expression of cyclin A protein via double immunostaining. RESULTS: Performing RT-PCR, Western blot and immunocytochemical analyses revealed that in human amniotic fluid in the background of Oct-4-negative cells a distinct population of cells can be found, which express Oct-4 in the nucleus. Oct-4-positive amniotic fluid cell samples also express stem cell factor, vimentin and alkaline phosphatase mRNA. The Oct-4-positive amniotic fluid cells are actively dividing, proven by the detection of cyclin A expression. CONCLUSIONS: The results presented here suggest that human amniotic fluid may represent a new source for the isolation of human Oct-4-positive stem cells without raising the ethical concerns associated with human embryonic research.

Amniotic Fluid↗
PubMed2002

Brca1 and differentiation.

Breast cancer is one of the most frequent malignancies affecting women. The human breast cancer gene 1 (BRCA1) gene is mutated in a distinct proportion of hereditary breast and ovarian cancers. Tumourigenesis in individuals with germline BRCA1 mutations requires somatic inactivation of the remaining wild-type allelle. Although, this evidence supports a role for BRCA1 as a tumour suppressor, the mechanisms through which its loss leads to tumourigenesis remain to be determined. Neither the expression pattern nor the described functions of human BRCA1 and murine breast cancer gene 1 (Brca1) can explain the specific association of mutations in this gene with the development of breast and ovarian cancer. Investigation of the role of Brca1 in normal cell differentiation processes might provide the basis to understand the tissue-restricted properties.

Animals↗
PubMed2002

MMP-2 and MMP-9 expression in breast cancer-derived human fibroblasts is differentially regulated by stromal-epithelial interactions.

Tissue remodeling is a key element in the local invasion and metastasis of malignant breast tumors. The degradation of extracellular matrix that is associated with this process is thought to be mediated by a number of Zn2+-dependent matrix metalloproteinases (MMPs). In most cases these enzymes are not produced by the malignant epithelium itself but by adjacent breast stroma, suggesting an important role for cell-cell interactions. We have analyzed Gelatinase A (MMP-2) and Gelatinase B (MMP-9) gene expression in a panel of six breast cancer cell lines and six primary cultures of stromal cells deriving from breast cancer biopsies. With one exception we did not detect MMP-2 or MMP-9 gene expression in any of the established tumor cell lines. Conversely, tumor stroma-derived fibroblasts expressed MMP-2 mRNA. although no MMP-9 mRNA was seen in RNase protection assays. When fibroblasts were cultured in the presence of media conditioned by MCF-7 tumor cells, MMP-2 enzyme production increased but MMP-9 activity remained undetectable. However, when fibroblasts and MCF-7 tumor cells were co-cultured together, MMP-9 was induced. These observations were confirmed by immunocytochemical analysis of co-cultures of MCF-7 and tumor-derived fibroblasts in which MMP-2 and MMP-9 protein expression was confined to stromal cells adjacent to MCF-7 tumor cells. No MMP-2 or MMP-9 staining was detected in monocultures of the two respective cell types. We conclude that MMP-2 expression is present in the stroma of malignant tumors and is increased by paracrine stimulation mediated by soluble factors. In contrast, MMP-9 expression tumor-derived fibroblasts requires direct contact with malignant tumor epithelium.

Breast Neoplasms↗
PubMedDate not supplied

The mouse mammary tumor virus-like env gene sequence is not detectable in breast cancer tissue of Austrian patients.

The mammary mouse tumor virus (MMTV) has been related to human breast cancer in previous studies, but these have yielded contradictory results. An MMTV env gene-like sequence was detectable in a relatively high proportion (38%) of human breast cancer tissues. The aim of this study was to determine the proportion of this 660 bp MMTV env gene-like sequence in a population of Austrian breast cancer patients. We performed PCR, repeat PCR, and nested PCR. We did not find any exogenous MMTV env gene sequences in the 50 DNA samples of human breast cancer tissue nor in 22 breast cancer cell lines including MCF-7, which has previously been described as a positive control.

Austria↗