Evaluation of protein expression and DNA methylation profiles detected by pyrosequencing in invasive breast cancer
| Autor: | I Rusnak, P Blasko, Michal Mego, Tomas Krivulcik, Ludovit Danihel, Vanda Repiská, Bozena Smolkova, Iveta Zmetakova, Marian Karaba, D Danis, Ivana Fridrichova, B Rychly, Juraj Benca, Viera Horvathova Kajabova, Juraj Pechan |
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| Rok vydání: | 2013 |
| Předmět: |
Adult
Cancer Research Breast Neoplasms Biology Metastasis Immunoenzyme Techniques chemistry.chemical_compound Young Adult Carcinoma medicine Biomarkers Tumor Humans Peripheral blood cell Neoplasm Invasiveness Aged Neoplasm Staging Carcinoma Ductal Breast Cancer Methylation Sequence Analysis DNA DNA Methylation Middle Aged medicine.disease Prognosis Molecular biology Adenocarcinoma Mucinous Carcinoma Lobular Oncology chemistry Case-Control Studies DNA methylation Cancer research Illumina Methylation Assay Female Neoplasm Grading DNA |
| Zdroj: | Neoplasma. 60(6) |
| ISSN: | 0028-2685 |
| Popis: | Breast carcinoma is the most common cancer with high mortality caused by metastatic disease. New molecular biomarkers predicting the tumour's metastatic potential would therefore improve metastasis prevention and personalised care. The aim of the study was to investigate the relationship between DNA methylation levels in invasivity and metastasising associated genes with aberrant protein expression and also to evaluate whether a similar DNA methylation level is present in the tumour and circulating cell-free DNA for utilising plasma DNA methylation as prognostic biomarker. By using pyrosequencing, we analysed DNA methylation levels of 11 genes, namely APC, ADAM23, CXCL12, ESR1, PGR B, CDH1, RASSF1A, SYK, TIMP3, BRMS1 and SOCS1 in tumour, plasma and peripheral blood cells from 34 patients with primary breast cancer, as well as plasma and peripheral blood cells from 50 healthy controls. Simultaneously, the expression of related proteins in paraffin-embedded tumour samples was evaluated by immunohistochemistry. Statistical analysis was performed by SPSS statistics 15.0 software. Tumour DNA hypermethylation was found in most commonly methylated RASSF1A (71.9%), APC (55.9%), ADAM23 (38%) and CXCL12 (34.4%) genes with methylation levels up to 86, 86, 53 and 64 %, respectively. In tumours, significantly higher methylation levels were found in nine genes, compared with the patients´ peripheral blood cell DNA. Furthermore, in patients methylation levels in peripheral blood cell DNA were significantly higher than in controls in CXCL12, ESR1 and TIMP3 genes, but the values did not exceed 15%. On the other hand, no correlations were observed in patients between DNA methylation in tumours and cell-free plasma DNA. Moreover, in patients and controls nearly identical values of cumulative DNA methylation (43.6 % ± 20.1 vs. 43.7 % ± 15.0) were observed in plasma samples. A variable spectrum from high to none expressions presented in tumour tissues in all of the proteins evaluated, however in APC and CXCL12 genes a visible decreasing trend of mean DNA methylation level with increasing expression of the corresponding protein was observed. The DNA methylation profiles manifested in our group of breast carcinomas are cancer specific, but they are not the only cause that affects the silencing of evaluated genes and the decrease of relevant protein products. The clinical utility of DNA methylation testing in peripheral blood cell DNA for cancer diagnosis and therapy need to be further investigated. |
| Databáze: | OpenAIRE |
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