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Dive into the research topics where Patrick Imesch is active.

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Featured researches published by Patrick Imesch.


Gynecologic Oncology | 2012

Indications and long-term clinical outcomes in 282 patients with pelvic exenteration for advanced or recurrent cervical cancer.

Ana-Maria Schmidt; Patrick Imesch; Daniel Fink; H. Egger

OBJECTIVE The aim of this study was to summarize the clinical experience at our clinic with pelvic exenteration as a treatment for cervical cancer with special regard to the indications and outcomes of specific patient groups. METHODS Medical records of 282 women who underwent pelvic exenteration to treat cervical cancer were analyzed. RESULTS In total, 70 patients (25%) underwent primary exenteration, and 212 (75%) underwent secondary exenteration. Exenteration was anterior for 14 (5%) patients, posterior for 6 (2%) and total for 262 (93%). The overall survival (OS) of the 282 patients was 41% at 5 years and 37% at 10 years. The disease-free survival at 5 years was 61%. For 133 patients for whom pelvic exenteration was a curative procedure, the OS was 64% at 5 years and 57% at 10 years. For cases of pelvic exenteration as a palliative intervention, the OS was 19% at 5 years and 18% at 10 years. No difference was seen in the OS at 5 years between patients who received primary and secondary operations. No significant difference in the OS was found regardless of whether the patients had positive pelvic lymph nodes, whereas in cases of paraaortic lymph node metastasis, the OS was significantly lower. Out of all of the procedures, 139 (49%) involved no perioperative or postoperative complications. One major complication was reported for 72 (26%) patients, two complications occurred for 42 patients (15%) and more than three complications were noted for 29 (10%) patients. CONCLUSION Pelvic exenteration is an effective technique with a high percentage of long-term survivors. To the best of our knowledge, our study involves the largest published number of patients treated with pelvic exenteration for a single gynecological cancer and shows that previous contraindications for pelvic exenteration, such as lymph node metastasis (especially when confined to the pelvic lymph nodes), older age or palliative intent, should be reconsidered.


International Journal of Molecular Sciences | 2013

ARID1A Mutations and PI3K/AKT Pathway Alterations in Endometriosis and Endometriosis-Associated Ovarian Carcinomas

Eleftherios P. Samartzis; Aurelia Noske; Konstantin J. Dedes; Daniel Fink; Patrick Imesch

Endometriosis is a common gynecological disease affecting 6%–10% of women of reproductive age and is characterized by the presence of endometrial-like tissue in localizations outside of the uterine cavity as, e.g., endometriotic ovarian cysts. Mainly, two epithelial ovarian carcinoma subtypes, the ovarian clear cell carcinomas (OCCC) and the endometrioid ovarian carcinomas (EnOC), have been molecularly and epidemiologically linked to endometriosis. Mutations in the gene encoding the AT-rich interacting domain containing protein 1A (ARID1A) have been found to occur in high frequency in OCCC and EnOC. The majority of these mutations lead to a loss of expression of the ARID1A protein, which is a subunit of the SWI/SNF chromatin remodeling complex and considered as a bona fide tumor suppressor. ARID1A mutations frequently co-occur with mutations, leading to an activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, such as mutations in PIK3CA encoding the catalytic subunit, p110α, of PI3K. In combination with recent functional observations, these findings strongly suggest cooperating mechanisms between the two pathways. The occurrence of ARID1A mutations and alterations in the PI3K/AKT pathway in endometriosis and endometriosis-associated ovarian carcinomas, as well as the possible functional and clinical implications are discussed in this review.


Modern Pathology | 2012

Loss of ARID1A /BAF250a-expression in endometriosis: a biomarker for risk of carcinogenic transformation?

Eleftherios P. Samartzis; Nicolas Samartzis; Aurelia Noske; André Fedier; Rosmarie Caduff; Konstantin J. Dedes; Daniel Fink; Patrick Imesch

Mutations of the tumor-suppressor gene ARID1A result in the loss of protein expression of the BRG-associated factor 250a (BAF250a), a large subunit of transcription-regulating Human SWI/SNF complexes, which have an important role in the control of cell proliferation and tumor suppression. ARID1A mutations are particularly frequent in endometriosis-associated ovarian clear cell and endometrioid carcinomas, and were recently described as a possible key mechanism and early step in the transformation of endometriosis into cancer. Here, we examined the immunohistochemical expression pattern of BAF250a in a tissue microarray including 74 endometriosis and 30 endometrium samples. Ovarian cancer samples (n=136) served as a control. Epithelial BAF250a expression was assessable in 90/104 (87%) and stromal BAF250a expression in 95/104 (91%) of the endometriosis, and endometrium cases due to lack of adequate tissue in some spots. Complete lack of BAF250a expression was observed in three endometriomas (n=3/20, 15%) and one deep-infiltrating endometriosis sample (n=1/22, 5%), but in none of the peritoneal endometriosis (n=0/16) and eutopic endometrium samples (n=0/30). A comparison of the mean immunoreactivity scores revealed a significantly lower expression rate of BAF250a in endometriomas compared with normal endometrium (P<0.0005), as well as peritoneal (P=0.003) and deep-infiltrating endometriosis (P=0.02). Our data demonstrates that a complete loss of BAF250a expression is observable in some endometriotic lesions, especially in endometriomas. In addition, we report that a partial loss of BAF250a expression is occurring in the form of cell clusters indicating a clonal loss of BAF250a expression in these cells. The loss of expression of the tumor-suppressor protein BAF250a in some endometriomas possibly indicates a risk of malignant transformation in these cases, which could be of importance in the determination of individual treatment strategies. However, its role and value as a prognostic parameter in endometriosis needs to be further studied.


Human Reproduction | 2011

The antibody-mediated targeted delivery of interleukin-10 inhibits endometriosis in a syngeneic mouse model

Kathrin Schwager; Frank Bootz; Patrick Imesch; Manuela Kaspar; Eveline Trachsel; Dario Neri

BACKGROUND Endometriosis is still a highly underdiagnosed disease, and the current medical and surgical treatment of endometriosis is associated with a high recurrence rate. This study investigates the use of derivatives of the human antibody F8, specific to the alternatively spliced extra-domain A of fibronectin (Fn), for the imaging and treatment of endometriosis. METHODS Immunohistochemistry and immunofluorescence was used to evaluate antigen expression in endometriotic tissue of human endometriosis and of a syngeneic mouse model of the disease. The in vivo targeting performance of a fluorescent derivative of the F8 antibody was assessed by imaging mice with endometriosis using a near-infrared fluorescence imager, 24 h following i.v. injection of the antibody conjugate. Furthermore, the mouse model was used for therapy experiments using two recombinant F8-based immunocytokines [F8-interleukin-10 (IL10) and F8-IL2] or saline for the treatment groups. RESULTS A very strong vascular expression of splice isoforms of Fn and of tenascin-C was observed in human endometriotic lesions by immunohistochemistry and immunofluorescence techniques. After i.v. administration, a selective accumulation of the F8 antibody in endometriotic lesions could be observed in a syngeneic mouse model. These targeting data were used as a basis for therapy experiments with a pro-inflammatory (F8-IL2) and an anti-inflammatory (F8-IL10) cytokine fusion protein of the F8 antibody. The average lesion size in the F8-IL10 treatment group was clearly reduced compared with the saline control group and with the F8-IL2 group, for which no therapeutic effects were observed. CONCLUSIONS The F8 antibody targets endometriotic lesions in vivo in a mouse model of endometriosis and may be used for the non-invasive imaging of the disease and for the pharmacodelivery of anti-inflammatory cytokines, such as IL10.


Anti-Cancer Drugs | 2009

Acquired vorinostat resistance shows partial cross-resistance to 'second-generation' HDAC inhibitors and correlates with loss of histone acetylation and apoptosis but not with altered HDAC and HAT activities.

Konstantin J. Dedes; Ioannis Dedes; Patrick Imesch; André O. von Bueren; Daniel Fink; André Fedier

Histone deacetylase (HDAC) inhibitors such as vorinostat (suberoylanilide hydroxamic acid), valproic acid, romidepsin (FK-228), and LBH589 comprise a relatively new class of potent anticancer agents. This study provides evidence for the potential of vorinostat to cause acquisition of multidrug resistance protein-independent resistance in HCT116 colon tumor cells. This acquired resistance is moderate (two-fold to three-fold), is nonreversible, and correlates with the loss of responses typically seen with HDAC inhibitors, that is the loss of acetylation of the histones H2A, H2B, H3, and H4, the loss of the G2/M checkpoint activation, and the loss of caspase 3-dependent and caspase 7-dependent apoptosis. This acquired resistance also associates with cross-resistance to the hydroxamate-class (LBH589 and JNJ26481585) and to the aliphatic acid-class (valproic acid) HDAC inhibitors but not to the benzamide-class (MGCD0103) and the cyclic peptide-class (romidepsin) HDAC inhibitors. The acquired HDAC inhibitor resistance described hereis not a result of altered HDAC and histone acetyltransferase activities and differs from that previously reported for romidepsin.


Fertility and Sterility | 2010

Romidepsin reduces histone deacetylase activity, induces acetylation of histones, inhibits proliferation, and activates apoptosis in immortalized epithelial endometriotic cells

Patrick Imesch; Daniel Fink; André Fedier

Romidepsin inhibited HDAC activity, produced acetylation of the histone proteins, up-regulated p21, and down-regulated cyclins B1 and D1, resulting in proliferation inhibition and apoptosis activation in 11z immortalized epithelial endometriotic cells. Our findings provide evidence that endometriotic cells are sensitive to the epigenetic effects of romidepsin and suggest that endometriosis may be therapeutically targeted by romidepsin.


PLOS ONE | 2014

Effect of MRE11 Loss on PARP-Inhibitor Sensitivity in Endometrial Cancer In Vitro

Romana Koppensteiner; Eleftherios P. Samartzis; Aurelia Noske; Adriana von Teichman; Ioannis Dedes; Myriam Gwerder; Patrick Imesch; Kristian Ikenberg; Holger Moch; Daniel Fink; Manuel Stucki; Konstantin J. Dedes

Aim of the study To evaluate the frequency of MRE11/RAD50/NBS1 (MRN)-complex loss of protein expression in endometrial cancers (EC) and to determine whether loss of MRE11 renders the cancer cells sensitive to Poly(ADP-ribose) polymerase (PARP)-inhibitory treatment. Methods MRN expression was examined in 521 samples of endometrial carcinomas and in 10 cancer cell lines. A putative mutation hotspot in the form of an intronic poly(T) allele in MRE11 was sequenced in selected cases (n = 26). Sensitivity to the PARP-inhibitor, BMN673 was tested in colony formation assays before and after MRE11 silencing using siRNA. Homologous recombination (HR) DNA repair was evaluated by RAD51-foci formation assay upon irradiation and drug treatment. Results Loss of MRE11 protein was found in 30.7% of EC tumours and significantly associated with loss of RAD50, NBS1 and mismatch repair protein expression. One endometrial cell line showed a markedly reduced MRE11 expression due to a homozygous poly(T) mutation of MRE11, thereby exhibiting an increased sensitivity to BMN673. MRE11 depletion sensitizes MRE11 expressing EC cell lines to the treatment with BMN673. The increased sensitivity to PARP-inhibition correlates with reduced RAD51 foci formation upon ionizing radiation in MRE11-depleted cells. Conclusion Loss of the MRE11 protein predicts sensitivity to PARP-inhibitor sensitivity in vitro, defining it as an additional synthetic lethal gene with PARP. The high incidence of MRE11 loss in ECs can be potentially exploited for PARP-inhibitor therapy. Furthermore, MRE11 protein expression using immunohistochemistry could be investigated as a predictive biomarker for PARP-inhibitor treatment.


PLOS ONE | 2014

The G protein-coupled estrogen receptor (GPER) is expressed in two different subcellular localizations reflecting distinct tumor properties in breast cancer

Eleftherios P. Samartzis; Aurelia Noske; Alexander Meisel; Zsuzsanna Varga; Daniel Fink; Patrick Imesch

Introduction The G protein-coupled estrogen receptor (GPER) is a novel estrogen receptor that mediates proliferative effects induced by estrogen but also by tamoxifen. The aim of our study was to analyze the frequency of GPER in a large collective of primary invasive breast carcinomas, with special emphasis on the subcellular expression and to evaluate the association with clinicopathological parameters and patient overall survival. Methods The tissue microarrays from formalin-fixed, paraffin embedded samples of primary invasive breast carcinomas (n = 981) were analyzed for GPER expression using immunohistochemistry. Expression data were compared to the clinicopathological parameters and overall survival. GPER localization was also analyzed in two immortalized breast cancer cell lines T47D and MCF7 by confocal immunofluorescence microscopy. Results A predominantly cytoplasmic GPER expression was found in 189 carcinomas (19.3%), whereas a predominantly nuclear expression was observed in 529 cases (53.9%). A simultaneous comparable positive expression of both patterns was found in 32 of 981 cases (3.2%), and negative staining was detected in 295 cases (30%). Confocal microscopy confirmed the occurrence of cytoplasmic and nuclear GPER expression in T47D and MCF7. Cytoplasmic GPER expression was significantly associated with non-ductal histologic subtypes, low tumor stage, better histologic differentiation, as well as Luminal A and B subtypes. In contrast, nuclear GPER expression was significantly associated with poorly differentiated carcinomas and the triple-negative subtype. In univariate analysis, cytoplasmic GPER expression was associated with better overall survival (p = 0.012). Conclusion Our data suggest that predominantly cytoplasmic and/or nuclear GPER expression are two distinct immunohistochemical patterns in breast carcinomas and may reflect different biological features, reason why these patterns should be clearly distinguished in histological evaluations. Prospective studies will be needed to assess whether the expression status of GPER in breast carcinomas should be routinely observed by clinicians, for instance, before implementing endocrine breast cancer treatment.


Reproductive Biology and Endocrinology | 2012

Expression of the G protein-coupled estrogen receptor (GPER) in endometriosis: a tissue microarray study

Nicolas Samartzis; Eleftherios P. Samartzis; Aurelia Noske; André Fedier; Konstantin J. Dedes; Rosmarie Caduff; Daniel Fink; Patrick Imesch

BackgroundThe G protein-coupled estrogen receptor (GPER) is thought to be involved in non-genomic estrogen responses as well as processes such as cell proliferation and migration. In this study, we analyzed GPER expression patterns from endometriosis samples and normal endometrial tissue samples and compared these expression profiles to those of the classical sex hormone receptors.MethodsA tissue microarray, which included 74 samples from different types of endometriosis (27 ovarian, 19 peritoneal and 28 deep-infiltrating) and 30 samples from normal endometrial tissue, was used to compare the expression levels of the GPER, estrogen receptor (ER)-alpha, ER-beta and progesterone receptor (PR). The immunoreactive score (IRS) was calculated separately for epithelium and stroma as the product of the staining intensity and the percentage of positive cells. The expression levels of the hormonal receptors were dichotomized into low (IRS < 6) and high (IRS > =6) expression groups.ResultsThe mean epithelial IRS (+/−standard deviation, range) of cytoplasmic GPER expression was 1.2 (+/−1.7, 0–4) in normal endometrium and 5.1 (+/−3.5, 0–12) in endometriosis (p < 0.001), of nuclear GPER 6.4 (+/−2.6, 0–12) and 6.8 (+/−2.9, 2–12; p = 0.71), of ER-alpha 10.6 (+/−2.4, 3–12) and 9.8 (+/−3.0, 2–12; p = 0.26), of ER-beta 2.4 (+/−2.2; 0–8) and 5.6 (+/−2.6; 0–10; p < 0.001), and of PR 11.5 (+/−1.7; 3–12) and 8.1 (+/−4.5; 0–12; p < 0.001), respectively. The mean stromal IRS of nuclear GPER expression was 7.7 (+/−3.0; 2–12) in endometrium and 10.8 (+/−1.7; 6–12) in endometriosis (p < 0.001), of ER-alpha 8.7 (+/−3.1; 2–12) and 10.6 (+/−2.4; 2–12; p = 0.001), of ER-beta 1.8 (+/−2.0; 0–8) and 5.4 (+/−2.5; 0–10; p < 0.001), and of PR 11.7 (+/−0.9; 8–12) and 10.9 (+/−2.0; 3–12; p = 0.044), respectively. Cytoplasmic GPER expression was not detectable in the stroma of endometrium and endometriosis. The observed frequency of high epithelial cytoplasmic GPER expression levels was 50% (n = 30/60) in the endometriosis and none (0/30) in the normal endometrium samples (p < 0.001). High epithelial cytoplasmic GPER expression levels were more frequent in endometriomas (14/20, 70%; p = 0.01), as compared to peritoneal (9/18, 50%) or deep-infiltrating endometriotic lesions (7/22, 31.8%). The frequency of high stromal nuclear GPER expression levels was 100% (n = 74/74) in endometriosis and 76.7% (n = 23/30) in normal endometrium (p < 0.001). The frequency of high epithelial nuclear GPER expression levels did not differ between endometriosis and normal endometrium.ConclusionsThe present data indicate a unique GPER expression pattern in endometriosis, especially in endometriomas as compared to the normal endometrium. The overexpression of GPER in endometriotic lesions suggests a potential role for GPER in the hormonal regulation of endometriosis, which should be taken into consideration for future hormonal treatment strategies.


Reproductive Sciences | 2013

The Expression of Histone Deacetylase 1, But Not Other Class I Histone Deacetylases, Is Significantly Increased in Endometriosis

Eleftherios P. Samartzis; Aurelia Noske; Nicolas Samartzis; Daniel Fink; Patrick Imesch

Class I histone deacetylases (HDACs-1-3) play an important role in steroid hormone–dependent gene expression and in modulating cell survival and proliferation. We analyzed their expression in a tissue microarray including 74 endometriosis samples and 30 normal endometrium controls. The mean HDAC-1 immunoreactivity score (IRS ± standard deviation) was 7.6 ± 2.5 in endometriosis and 5.3 ± 2.3 in normal endometrium (P < .001). In contrast, the IRSs of HDAC-2 and -3 were 11.7 ± 0.7 and 11.8 ± 1.1 in endometriosis and 11.6 ± 1.0 and 11.9 ± 0.4 in normal endometrium (P = .7 and P = .2), respectively. Significant correlations were found between HDAC-1 and estrogen (-alpha/-beta) and progesterone receptor expression. In conclusion, HDAC-1, but not HDAC-2/-3, was significantly increased in endometriosis and associated with steroid hormone receptor expression that may reflect interdependence. In context with the literature, specific inhibitors of HDAC-1 may have inhibitory activities similar to those of broad-spectrum HDAC inhibitors and may be clinically tolerated, which would increase their chance as an option in the treatment of endometriosis.

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