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Dive into the research topics where Sandra Waalkes is active.

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Featured researches published by Sandra Waalkes.


BMC Cancer | 2010

Fibronectin 1 mRNA expression correlates with advanced disease in renal cancer

Sandra Waalkes; Faranaz Atschekzei; Mario W. Kramer; Jörg Hennenlotter; Gesa Vetter; Jan U. Becker; Arnulf Stenzl; Axel S. Merseburger; Andres J. Schrader; Markus A. Kuczyk; Jürgen Serth

BackgroundFibronectin 1 (FN1) is a glycoprotein involved in cellular adhesion and migration processes. The aim of this study was to elucidate the role of FN1 in development of renal cell cancer (RCC) and to determine a prognostic relevance for optimal clinical management.Methods212 renal tissue samples (109 RCC, 86 corresponding tissues from adjacent normal renal tissue and 17 oncocytomas) were collected from patients undergoing surgery for renal tumors and subjected to total RNA extraction. Detection of FN1 mRNA expression was performed using quantitative real time PCR, three endogenous controls, renal proximal tubular epithelial cells (RPTEC) as biological control and the ΔΔCt method for calculation of relative quantities.ResultsMean tissue specific FN1 mRNA expression was found to be increased approximately seven fold comparing RCC and corresponding kidney control tissues (p < 0.001; ANOVA). Furthermore, tissue specific mean FN1 expression was increased approx. 11 fold in clear cell compared to papillary RCC (p = 9×10-5; Wilcoxon rank sum test). Patients with advanced disease had higher FN1 expression when compared to organ-confined disease (p < 0.001; Wilcoxon rank sum test). Applying subgroup analysis we found a significantly higher FN1 mRNA expression between organ-confined and advanced disease in the papillary and not in the clear cell RCC group (p = 0.02 vs. p = 0.2; Wilcoxon rank sum test). There was an increased expression in RCC compared to oncocytoma (p = 0.016; ANOVA).ConclusionsTo our knowledge, this is the first study to show that FN1 mRNA expression is higher in RCC compared to normal renal tissue. FN1 mRNA expression might serve as a marker for RCC aggressiveness, indicating early systemic progression particularly for patients with papillary RCC.


BJUI | 2012

GATA5 CpG island methylation in renal cell cancer: a potential biomarker for metastasis and disease progression.

Inga Peters; Hendrik Eggers; Faranaz Atschekzei; Jörg Hennenlotter; Sandra Waalkes; Wolfgang Tränkenschuh; Anika Großhennig; Axel S. Merseburger; Arnulf Stenzl; Markus A. Kuczyk; Jürgen Serth

Whats known on the subject? and What does the study add?


Urologia Internationalis | 2011

Decreased Galectin-8 Is a Strong Marker for Recurrence in Urothelial Carcinoma of the Bladder

Mario W. Kramer; Sandra Waalkes; Jürgen Serth; Jörg Hennenlotter; Hossein Tezval; A. Stenzl; Markus A. Kuczyk; Axel S. Merseburger

Objective: To investigate galectin-8 expression patterns in normal urothelium and bladder cancer specimens and to elucidate its prognostic value. Materials and Methods: 162 samples of non-muscle-invasive transitional cell carcinoma, 25 samples of muscle-invasive transitional cell carcinoma and 10 samples of normal urothelium were investigated by immunohistochemistry using tissue microarrays. Complete patient and tumor characteristics were compared with galectin-8 staining patterns. The likelihood of tumor recurrence and progression was analyzed based on a 3-year follow-up. Results: Loss of galectin-8 was associated with the likelihood of tumor recurrence in univariate (p < 0.05) and multivariate analyses (p < 0.01). No significance was observed for tumor progression. Patients whose specimens showed weak galectin-8 expression had a shorter recurrence-free interval (42 vs. 12 months; p < 0.01, log-rank test). All of the 10 normal urothelium samples showed high galectin-8 expression. Decreased staining was found to be associated with higher tumor stages and grades (p < 0.0001, one-way ANOVA). A significant difference was found comparing normal urothelium with any tumor stage (p < 0.01), pTa vs. pT1 tumors (p < 0.05) and non-muscle-invasive vs. muscle-invasive tumors (p < 0.0001). Conclusions: Loss of galectin-8 might be an early step in the development of malignant lesions of the bladder and is a significant independent predictor of recurrence.


Epigenetics | 2012

SFRP1 CpG island methylation locus is associated with renal cell cancer susceptibility and disease recurrence

Faranaz Atschekzei; Jörg Hennenlotter; Stefanie Jänisch; Annika Großhennig; Wolfgang Tränkenschuh; Sandra Waalkes; Inga Peters; Thilo Dörk; Axel S. Merseburger; Arnulf Stenzl; Markus A. Kuczyk; Jürgen Serth

Loss of the secreted Fzd-related protein 1 (SFRP1) and concurrent alteration of the SFRP1/WNT pathway are frequently observed in human cancers such as in renal cell cancer (RCC). Whether methylation of a SFRP1 CpG island locus in normal human solid tissues is associated with increased tissue specific cancer risk has not been determined to date. Here we measure the cancer risk attributable to SFRP1 DNA methylation in renal tissue. Pyrosequencing of bisulfite treated DNA was used for a case-control study including 120 normal-appearing renal tissues of autopsy specimens and 72 normal-appearing tissues obtained from tumor adjacent areas, and a cross sectional study of 96 RCCs. Association of methylation with demographic risk factor age, clinicopathological parameters and course of patients was investigated. We show significant hypermethylation of a SFRP1 CpG island locus in normal-appearing renal tissues from RCC patients compared with normal-appearing autopsy kidney tissues. Inter quartile analysis revealed a 6-, 13- and 11-fold increased cancer risk for the second, third and fourth quartiles of methylation in the age matched subgroup of tissues (p = 0.001, p = 1.3E-6, p = 6.9E-6). Methylation in autopsy tissues increased with age and methylation in tumors was an independent predictor of recurrence free survival. SFRP1 DNA methylation, accumulates with age in normal-appearing kidney tissues and is associated with increased renal cancer risk, suggesting this CGI sub region as an epigenetic susceptibility locus for RCC. Our data underline the need to further analyze the tissue specific risks conferred by methylated loci for the development of human cancers.


Expert Review of Anticancer Therapy | 2009

Sorafenib reveals efficacy in sequential treatment of metastatic renal cell cancer

Axel S. Merseburger; Annika Simon; Sandra Waalkes; Markus A. Kuczyk

Metastatic renal cell carcinoma (mRCC) is a highly vascularized tumor with a generally poor prognosis. It is largely resistant to conventional cancer treatment, including most schemes of hormonal and cytokine therapy as well as to modern chemotherapy. Although IFN-α has been the first choice in mRCC treatment strategies for more than a decade, recent recommendations of the European Association of Urology focus on so-called molecular-targeted therapies, with multikinase inhibitors, such as sorafenib and sunitinib, blocking the progression of cell proliferation and tumor angiogenesis, as preferential therapy. Sorafenib targets the VEGF receptor, the PDGF receptor β and, finally, Raf kinase, and is approved for patients who have either received cytokines or are unsuitable for such a therapy. Although targeted therapies reveal superior efficacy compared with previous cytokine-based approaches, they do not cure patients with metastatic disease. Therefore, following tumor progression, most patients require a second-line or sequential therapy during the further progress of the disease. Owing to the fact that optimal sequencing of these new agents has not been fully elucidated, some recent mainly retrospective studies compared the sequence of sorafenib and sunitinib in order to assess the best clinical benefit in mRCC patients. Apparently, no cross-resistance could be observed in any trial, and most results demonstrated a superior efficacy of a sequence strategy when sorafenib was applied as first-line treatment. Regarding current investigations, the aim of the present article is to address and critically discuss the clinical data concerning the efficacy of sorafenib as part of a sequential treatment of mRCC.


World Journal of Surgical Oncology | 2011

Partial nephrectomy using porcine small intestinal submucosa

Thomas J. Schnoeller; Robert de Petriconi; R. Hefty; Florian Jentzmik; Sandra Waalkes; Friedemann Zengerling; Mark Schrader; Andres J. Schrader

BackgroundWhenever technically feasible and oncologically justified, nephron-sparing surgery is the current standard of care for localized renal cell carcinomas (RCC). The main complications of partial nephrectomy, especially for large and centrally located tumors, are urinary leakage and parenchymal bleeding. We prospectively evaluated the pros and cons of using porcine small intestinal submucosa (SIS, Surgisis®) to close the renal defect after nephron-sparing surgery.MethodsWe used Surgisis® (Cook medical, Bloomington, IN, USA) to secure and compress the capsular defect after tumor resection in 123 patients submitted to 129 partial nephrectomies between August 2003 and February 2011.ResultsThe median tumor size was 3.7 cm (range 1.1-13.0 cm). Procedures were performed with cold ischemia in 24 cases (18.2%), with warm ischemia in 46 (35.6%), and without ischemia in 59 cases (44.8%). In the total group of patients, 4 (3.1%) developed urinary fistula, and only 2 (1.6%) required postoperative transfusions due to hemorrhage after the application of the small intestinal submucosa membrane.ConclusionSmall intestinal submucosa is an easy-to-use biomaterial for preventing complications such as postoperative bleeding and urinary fistula in nephron-sparing surgery, especially in cases where tumor excision causes significant renal capsular and/or renal pelvic defects.


Biomarkers in Medicine | 2011

Caveolin 1 mRNA is overexpressed in malignant renal tissue and might serve as a novel diagnostic marker for renal cancer.

Sandra Waalkes; Hendrik Eggers; Hanna Blasig; Faranaz Atschekzei; Mario W. Kramer; Jörg Hennenlotter; Wolfgang Tränkenschuh; Arnulf Stenzl; Jürgen Serth; A.J. Schrader; Markus A. Kuczyk; Axel S. Merseburger

BACKGROUND & AIM Caveolae play a significant role in disease phenotypes, such as cancer, diabetes, bladder dysfunction and muscular dystrophy. The aim of this study was to elucidate the expression of caveolin (CAV)1 in the development of renal cell cancer (RCC) and to determine a possible prognostic relevance for optimal clinical management. MATERIAL & METHODS 109 RCC and 81 corresponding normal tissue specimens from the same kidney were collected from patients undergoing surgery for renal tumors and subjected to total RNA extraction. Quantification of CAV1 mRNA expression was performed using real-time reverse transcription PCR with three endogenous controls for renal proximal tubular epithelial cells and the ΔΔCt method for calculation of relative quantities. Expression levels were correlated to clinical variables. RESULTS Tissue-specific mean CAV1 expression was significantly increased in RCC compared with normal renal tissue (p = 0.0003; paired Wilcoxon rank sum test). CAV1 expression was increased 1.9-fold in clear cell RCC compared with papillary RCC (p = 1.48 × 10(-7); unpaired Wilcoxon rank sum test). Patients with advanced disease had higher CAV1 expression when compared with organ-confined disease (p = 0.019; unpaired Wilcoxon rank sum test). Moreover, mean tissue-specific CAV1 expression was increased in patients with distant metastasis at the time of diagnosis compared with patients without metastasis (p = 0.0058; unpaired Wilcoxon rank sum test). CONCLUSION To our knowledge, this is the first study to show that CAV1 mRNA expression, using quantitative real-time PCR, is significantly higher in RCC compared with normal renal tissue and increases with tumor stage. CAV1 mRNA expression might serve as a candidate biomarker for objective prognosis indicating RCC aggressiveness. Our data encourage further investigations to determine the role of CAV1 in RCC.


Onkologie | 2011

Does Male Sex Influence the Prognosis of Patients with Renal Cancer

Sandra Waalkes; Hendrik Rott; Thomas R. W. Herrmann; Gerd Wegener; Mario W. Kramer; Axel S. Merseburger; Mark Schrader; Rainer Hofmann; Markus A. Kuczyk; Andres J. Schrader

Background: The aim of this study was to investigate the influence of sex on stage, grade, subtype, and prognosis of patients with renal cell carcinoma (RCC). Patients and Methods: This study included 1,810 patients treated by surgery for RCC at the University Hospitals of Hannover and Marburg between 1990 and 2005. The median follow-up was 54 months. Results: Of all the patients, 1,167 (64.5%) were men and 643 (35.5%) were women. Men were significantly younger (mean, 61.4 vs. 63.5 years; p < 0.001), and suffered more frequently from advanced tumor stages (45.2 vs. 37.6%; p = 0.002) and higher tumor grades (14.1 vs. 11.1%; p = 0.003). Kaplan Meier curves revealed a significant difference in cancer-specific survival between men and women (5-year survival 64.7 vs. 74.0%; p = 0.002). However, unlike tumor stage, grade, and N/M status, sex could not be retained as a significant independent prognostic marker in multivariate analysis. Conclusions: RCC in men is characterized by higher tumor stages and more frequent metastasis at diagnosis along with inferior tumor-specific survival. However, as sex failed to qualify as an independent prognostic marker for cancer-specific survival, delayed diagnosis due to insufficient or neglected (routine) medical check-up and/or more aggressive tumor biology could be concurrently causative for the higher incidence of RCC in men.


Immunotherapy | 2010

Present state of target therapy for disseminated renal cell carcinoma

Sandra Waalkes; Mario W. Kramer; Thomas R. W. Herrmann; Andres J. Schrader; Markus A. Kuczyk; Axel S. Merseburger

Both experimental and clinical researches focusing on advanced kidney cancer have increased continuously since the successful introduction of targeted therapy in the treatment of advanced metastatic renal cell carcinoma. Being refractory to conventional hormone therapy, chemotherapy or radiotherapy, renal cell carcinoma has become a model tumor for the development and evaluation of diverse novel targeted drugs. This review highlights currently available agents and summarizes evidence-based data regarding their effectiveness in metastatic renal cell carcinoma. Furthermore, the role of debulking tumor nephrectomy followed by systemic therapy as part of an optimum treatment algorithm is being elucidated.


BMC Cancer | 2013

Reduced mrna expression level of corticotropin- releasing hormone-binding protein is associated with aggressive human kidney cancer

Hossein Tezval; Faranaz Atschekzei; Inga Peters; Sandra Waalkes; Jörg Hennenlotter; A. Stenzl; Jan U. Becker; Axel S. Merseburger; Markus A. Kuczyk; Jürgen Serth

BackgroundSignificance of Urocortin (Ucn or UcnI), Ucn2, Ucn3 and their receptors, Corticotropin Releasing Factor Receptor 1 and 2 (CRFR1 and CRFR2), and the binding protein, Corticotropin-Releasing Hormone-Binding Protein (CRHBP) in oncology is growing rapidly. The objective of our study was to assess the expression of the CRHBP mRNA and protein in renal cancer.MethodsTumoral tissues of 78 patients with clear cell renal cell cancer and their corresponding normal tissues were analyzed using quantitative mRNA expression analysis for detection of mRNA expression level. Protein expression and tissue localization of CRHBP protein in renal specimens was evaluated using western blotting, immunohistochemistry and double immunofluorescence, respectively.ResultsWe found an approx. 33 fold decrease of average CRHBP mRNA level in tumoral tissues compared to paired normal tissues (p<0.001). Diminished CRHBP mRNA expression was positively correlated with advanced, metastasized and higher stage of disease (p<0.001, p=0.026, p=0.028 respectively). CRHBP protein was detected in glomeruli and proximal tubules of normal kidney while none or weak immunopositivity was found in cc-RCC (p<0.001).ConclusionsThe expression analysis of CRHBP shows that cc-RCC is characterized by a significant loss of CRHBP mRNA expression that furthermore is associated with a more aggressive state of tumors. Depletion of CRHBP proteins also indicate that the protein as part of the UCN system may be involved in renal carcinogenesis.

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M.A. Kuczyk

University of Tübingen

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