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Dive into the research topics where Tanja Ignatov is active.

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Featured researches published by Tanja Ignatov.


American Journal of Obstetrics and Gynecology | 2010

Role of GPR30 in endometrial pathology after tamoxifen for breast cancer.

Tanja Ignatov; Holm Eggemann; Andrzej Semczuk; Bobbie Smith; Joachim Bischoff; Albert Roessner; S. Costa; Thomas Kalinski; Atanas Ignatov

OBJECTIVE This study was undertaken to evaluate the potential role of G-protein-coupled estrogen receptor in endometrial pathology associated with tamoxifen treatment of breast cancer patients. STUDY DESIGN We investigated whether G-protein-coupled estrogen receptor plays a role in mediating proliferating effect of tamoxifen in endometrial carcinoma cells. These results were compared with the G-protein-coupled estrogen receptor expression pattern in endometrial tissue from a cohort of 95 breast cancer patients, who received tamoxifen or another adjuvant therapy. RESULTS In vitro tamoxifen significantly stimulated the mitogen-activated protein kinase phosphorylation and cell proliferation of endometrial cell lines via G-protein-coupled estrogen receptor. In vivo, there was a significant correlation between G-protein-coupled estrogen receptor expression and the tamoxifen-induced endometrial pathology (P = .006). Moreover, G-protein-coupled estrogen receptor positivity was predictive of an earlier development of symptoms, such as bleeding or suspect endometrial thickness, induced by tamoxifen therapy (P = .019). CONCLUSION G-protein-coupled estrogen receptor plays an important role in tamoxifen-induced endometrial abnormalities.


Cancer Science | 2010

APC promoter hypermethylation is an early event in endometrial tumorigenesis

Atanas Ignatov; Joachim Bischoff; Tanja Ignatov; Christa Schwarzenau; Thomas Krebs; Doerthe Kuester; Serban D. Costa; Albert Roessner; Andrzej Semczuk; Regine Schneider-Stock

The aim of the current study was to investigate the role of promoter methylation of adenomatous polyposis coli (APC) and epithelial cadherin (E‐cadherin) genes in endometrial tumorigenesis. The methylation status of both genes was investigated in 43 cases of normal endometrium, 21 simple hyperplasia, 17 atypical hyperplasia, and 86 endometrial carcinoma (EC). Additionally, the methylation pattern of both genes was analyzed in 24 primary ECs and their corresponding metastases. DNA methylation of the APC gene increased from atypical hyperplasia (23.5%) to endometrial carcinoma, reaching its highest level of 77.4% in early stage cancer (FIGO I and II) and decreasing stepwise to 24.2% in advanced stage carcinomas (FIGO III and IV). No methylation of APC was found in normal endometrium or simple hyperplasia. Methylation of E‐cadherin was found only in EC (22.1%). The mean age of the patients with aberrant APC methylation was 68.8 years and was significantly higher compared to the mean age (60.9 years) of the patients without methylation of APC promoter (P = 0.02). APC promoter methylation significantly correlated with decreased protein expression of APC (P = 0.039), with increased expression of the Ki‐67 proliferative marker (P = 0.006) and decreased metastatic potential (P = 0.002). There was no correlation between APC and E‐cadherin methylation patterns and the other clinicopathologic features, nor with patient outcome. Our results suggest that hypermethylation of APC promoter region is an early event in endometrial tumorigenesis. (Cancer Sci 2009)


Cancer Investigation | 2013

GPER-1 Expression Decreases During Breast Cancer Tumorigenesis

Tanja Ignatov; Christine Weißenborn; Angela Poehlmann; Antje Lemke; Andrzej Semczuk; Albert Roessner; Serban-Dan Costa; Thomas Kalinski; Atanas Ignatov

GPER-1 protein expression was immunohistochemically examined in 164 primary breast cancer specimens and their matched normal breast epithelium. GPER-1 down-regulation correlated significantly with increased histological grading (p = .015), lymph node metastases (p = .032), and negative estrogen receptor status (p = .018). The decrease of GPER-1 expression in breast cancer tissue, relative to normal tissue, was associated with poor overall survival (p = .043) and disease-free survival (p = .037) and remained a significant unfavorable factor in multivariate analysis for DFS (HR = 1.569; 95% CI, 1.024–2.797; p = .041) and OS (HR = 2.082; 95% CI, 1.248–4.773; p = .039). Thus aberrant GPER-1 expression seems to be an important factor in breast cancer progression.


Journal of Cancer Research and Clinical Oncology | 2014

GPER functions as a tumor suppressor in triple-negative breast cancer cells

Christine Weißenborn; Tanja Ignatov; Hans-Joachim Ochel; Serban-Dan Costa; Ana Claudia Zenclussen; Zoya Ignatova; Atanas Ignatov

AbstractBackground The orphan, membrane-bound estrogen receptor (GPER) is expressed at high levels in a large fraction of breast cancer patients and its expression is favorable for patients’ survival.MethodsWe investigated the role of GPER as a potential tumor suppressor in triple-negative breast cancer cells MDA-MB-231 and MDA-MB-468 using cell cycle analysis and apoptosis assay. The constitutive activity of GPER was investigated.Results GPER-specific activation with G-1 agonist inhibited breast cancer cell growth in concentration-dependent manner via induction of the cell cycle arrest in G2/M phase, enhanced phosphorylation of histone H3 and caspase-3-mediated apoptosis. Analysis of the methylation status of the GPER promoter in the triple-negative breast cancer cells and in tissues derived from breast cancer patients revealed that GPER amount is regulated by epigenetic mechanisms and GPER expression is inactivated by promoter methylation. Furthermore, GPER expression was induced by stress factors, such as radiation, and GPER amount inversely correlated with the p53 expression level.ConclusionsOverall, our results establish the protective role in breast cancer tumorigenesis, and the cell surface expression of GPER makes it an excellent potential therapeutic target for triple-negative breast cancer.


Gynecologic and Obstetric Investigation | 2010

Interval between Port Catheter Flushing Can Be Extended to Four Months

Atanas Ignatov; Tanja Ignatov; Andrei Taran; Bobbie Smith; Serban-Dan Costa; Joachim Bischoff

Background: Little is known about proper interval periods between the flushings of totally implantable access ports after completion of chemotherapy. Manufacturer guidelines recommend flushing catheters every 4 weeks. Methods: This retrospective study examined whether flushing less than every 4 weeks conferred any benefit. Results: 349 totally implanted access ports were divided into four groups based on the different durations of the intervals between flushings. Sixteen (4.6%) complications were observed in the study population. Conclusion: Our results demonstrate that extending the flushing interval to up to 4 months remains medically safe and drastically reduces the costs.


Journal of Cancer Research and Clinical Oncology | 2014

GPER functions as a tumor suppressor in MCF-7 and SK-BR-3 breast cancer cells.

Christine Weißenborn; Tanja Ignatov; Angela Poehlmann; Anja K. Wege; S. Costa; Ana Claudia Zenclussen; Atanas Ignatov

AbstractPurposeThe orphan, membrane-bound estrogen receptor (GPER) is expressed at high levels in a large fraction of breast cancer patients, and its expression is favorable for patients’ survival. We investigated the role of GPER as a potential tumor suppressor in MCF-7 and SK-BR-3 breast cancer cells.MethodsThe effect of GPER agonist G-1 in cell culture was used to determine whether GPER inhibit cell growth. The methylation status of GPER promoter was investigated by methylation-specific PCR.Results GPER-specific agonist G-1 inhibited breast cancer cell proliferation in concentration-dependent manner via induction of the cell cycle arrest in M-phase, enhanced phosphorylation of histone 3 and cell apoptosis. Analysis of the methylation status of the GPER promoter in MCF-7 and SK-BR-3 cells revealed that GPER expression is regulated by epigenetic mechanisms and GPER expression is inactivated by promoter methylation. Overall, our results are consistent with our recent findings in triple-negative breast cancer cells, and the cell surface expression of GPER makes it an excellent potential therapeutic target for non-triple-negative breast cancer.


Endocrine-related Cancer | 2015

Moderate HER2 expression as a prognostic factor in hormone receptor positive breast cancer

Holm Eggemann; Tanja Ignatov; Elke Burger; Eva Johanna Kantelhardt; Franziska Fettke; Christoph Thomssen; Serban-Dan Costa; Atanas Ignatov

Overexpression and/or amplification of human epidermal growth factor receptor 2 (HER2) is associated with poor prognosis in breast cancer and predicts response to anti-HER2 therapy in breast cancer. The prognostic relevance of moderate expression of HER2 is unclear. Data of 9872 patients with primary nonmetastatic breast cancer from the cancer registries of Magdeburg and Halle, Germany, were analyzed retrospectively. A total of 5907 patients with complete data sets including follow-up were eligible for analysis. HER2 status was determined as recommended by international guidelines. Of 5907 patients investigated, 5023 (68.4%) had HER2 0 and 1+ expression and 884 (12.0%) had HER2 (2+)/HER2- expression. Patients with hormone receptor positive (HR+) and HER2 (2+) tumors had a shorter median disease-free survival (DFS; P<0.0001) and breast cancer specific survival (BCSS; P=0.019) than HR+ patients with HER2 (0/1+) tumors. Among patients with HR- breast cancer there was no significant difference between HER2 (2+) and HER2 (0/1+) tumors. In multivariate analysis after adjustment for other prognostic factors, HER2 (2+) status remained an unfavorable prognostic factor for DFS (hazard ratio (HR)=1.217, 95% CI=1.052-1.408; P=0.008) but not for BCSS (HR=1.045, 95% CI=0.926-1.178; P=0.474). The HER2 (2+) status is an unfavorable prognostic factor for survival of patients with HR+ breast cancer. The impact of anti-HER2 therapy in this group of patients should be evaluated.


American Journal of Reproductive Immunology | 2013

HO-1 As Modulator of the Innate Immune Response in Pregnancy

Kristina Kahlo; Sara Fill Malfertheiner; Tanja Ignatov; Federico Jensen; Serban-Dan Costa; Anne Schumacher; Ana Claudia Zenclussen

The immune modulatory effect of heme oxygenase‐1 (HO‐1) is well documented in studies about sepsis and transplantation. This work evaluates the influence of HO‐1 on the innate immune response during pregnancy.


Gynecologic Oncology | 2017

Management of elderly women with endometrial cancer

Holm Eggemann; Tanja Ignatov; Elke Burger; Serban-Dan Costa; Atanas Ignatov

BACKGROUND Elderly women with endometrial cancer receive less therapy in comparison with their younger counterparts. The exact reason(s) for this treatment strategy remains unclear. PATIENTS AND METHODS We performed a multicenter, retrospective registry-based study of 1550 patients with endometrial cancer. The outcome measure was the reason for not performing the indicated treatment. RESULTS Median follow-up was 76.8months. A total of 1550 women were eligible for analysis: 353 (22.7%) were younger than 60years, 521 (33.6%) 61-70years, 515 (33.2%) 71-80years, and 161 (10.4%) were aged 81years old and older. Elderly women were more likely to have non-endometrioid, undifferentiated endometrial cancer at an advanced stage. Patients younger than 60years were more likely to receive lymphadenectomy, brachytherapy, external-beam radiotherapy (EBRT) and systemic therapy compared with the group of patients aged older than 70years. We investigated the reason why elderly women were undertreated. The rate of indicated therapies that were not recommended by the physicians proportionally increased with an increase in patient age. Interestingly, the rate of contraindications because of performance status and/or medical disease also increased proportionally with increasing patient age. Notably, in the groups of patients older than 70years, patient refusal was a very uncommon reason for failure to perform the indicated therapy. CONCLUSIONS Elderly women with EC are more likely undertreated because the therapy was not recommended by the physicians based on performance status and medical diseases rather than patient refusal.


Cancer Investigation | 2017

GPER Promoter Methylation Controls GPER Expression in Breast Cancer Patients

Christine Weissenborn; Tanja Ignatov; Norbert Nass; Thomas Kalinski; Serban-Dan Costa; Ana Claudia Zenclussen; Atanas Ignatov

ABSTRACT Recently, we found that G-protein-coupled estrogen receptor (GPER) protein expression decreased during breast carcinogenesis, and that GPER promoter is methylated. Here we analyzed GPER promoter methylation in 260 primary breast cancer specimens by methylation-specific polymerized chain reaction. The results demonstrated that GPER protein down-regulation significantly correlated with GPER promoter hypermethylation (p < .001). Comparison of 108 tumors and matched normal breast tissues indicated a significant GPER down-regulation in cancer tissues correlating with GPER promoter hypermethylation (p < .001). The latter was an unfavorable factor for overall survival of patients with triple-negative breast cancer (p = .025). Thus GPER promoter hypermethylation might be used as a prognostic factor.

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Dive into the Tanja Ignatov's collaboration.

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Atanas Ignatov

Otto-von-Guericke University Magdeburg

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Serban-Dan Costa

Otto-von-Guericke University Magdeburg

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Holm Eggemann

Otto-von-Guericke University Magdeburg

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Elke Burger

Otto-von-Guericke University Magdeburg

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Albert Roessner

Otto-von-Guericke University Magdeburg

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Thomas Kalinski

Otto-von-Guericke University Magdeburg

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Ana Claudia Zenclussen

Otto-von-Guericke University Magdeburg

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Christine Weißenborn

Otto-von-Guericke University Magdeburg

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Joachim Bischoff

Otto-von-Guericke University Magdeburg

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S. Costa

Otto-von-Guericke University Magdeburg

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