Sebastian Hoffmann

Retinoic acid inhibits angiogenesis and tumor growth of thyroid cancer cells.

The anti-proliferative effect of retinoic acid (RA) has been documented for various tumors. Some 40% of patients with advanced and poorly differentiated thyroid cancer have been shown to respond to RA with increased uptake of radioiodine. It has been suggested that these effects may be caused by redifferentiation. Presently, little is known about the effects of RA on tumor angiogenesis, a prerequisite for growth and metastatic spread. The aim of the current study was to determine, whether tumor-induced angiogenesis of thyroid cancer is affected by RA. In vitro, the effect of 0.1/10 microM 13-cis RA on tumor cell number (MTT assay) and secretion of VEGF (ELISA) was analyzed in three thyroid cancer cell lines (FTC 236, C634 and XTC), as well as in endothelial cells (HUVEC) over several passages. In vivo, tumor growth, VEGF-expression and microvessel density (VSD) of RA treated thyroid cancer cells after xenotransplantation to nude mice was evaluated by morphometric analysis. In vitro, thyroid cancer cell lines responded to RA with reduced proliferation, ranging from 26 to 34% after 2 weeks of treatment and with up to 80% reduced secretion of VEGF. In vivo, tumor volumes of animals receiving RA were reduced by 33% (FTC 236), 27% (C643) and 6% (XTC), respectively. VSD of experimental tumors was diminished in the FTC 236 (25%) and the C643 cell line (15%), and almost unchanged in XTC tumors (7%). In vivo, VEGF-expression and apoptosis were not significantly affected by RA. In vitro, proliferation of HUVEC was inhibited by conditioned medium of C643 cells pretreated with RA (0.1/10 microM), as well as by administration of RA (0.1/10 microM). This study confirms thyroid tumor cell growth to be inhibited by RA. It demonstrates a decrease of in vitro VEGF accumulation and reduction of VSD in experimental undifferentiated thyroid carcinoma, suggesting that reduced angiogenesis may be an important mechanism responsible for the therapeutic effect of RA in thyroid cancer. Moreover, a direct anti-proliferative effect of RA on human endothelial cells is suggested.

DIAGNOSTIC SCORE IN APPENDICITIS. VALIDATION OF A DIAGNOSTIC SCORE (ESKELINEN SCORE) IN PATIENTS IN WHOM ACUTE APPENDICITIS IS SUSPECTED

Background and aimAt times, the diagnosis of acute appendicitis may be difficult. However, for minimum morbidity to be obtained, early and accurate diagnosis is essential. This study aimed to validate a scoring system proposed by Eskelinen et al. as an aid in making the diagnosis of appendicitis.Patients and methodsThe prospectively documented data of a consecutive series of 2,359 patients admitted for suspicion of appendicitis were used for validation. Accuracy and positive predictive value were defined as the main overall performance parameters, as was the rate of unnecessary operations to assess changes of patient management. Overall performance was assessed by receiver–operator characteristics (ROC) analysis.ResultsOf 2,359 patients, 662 were proven to have acute appendicitis (prevalence of 28%). The overall sensitivity, specificity, positive and negative predictive value, and accuracy of the score were 0.79, 0.85, 0.68, 0.91 and 0.835 at a cut-off value of 55. Calibration of the score’s cut-off value to 57 yielded more favourable results (0.72, 0.91, 0.76, 0.9 and 0.86), and the rate of unnecessary operations declined from 26.6% to 15.4% (P<0.05, χ2). ROC analysis revealed an area index of 0.91.ConclusionThe Eskelinen score delivered acceptable clinical results only after calibration to a cut-off value of 57. The data from this study suggest the investigation of whether a calibrated score might be particularly instrumental in the pre-admission evaluation of the patient in whom appendicitis is suspected.

Evaluation of Aurora kinase inhibition as a new therapeutic strategy in anaplastic and poorly differentiated follicular thyroid cancer

Due to an unfavorable prognosis using the usual therapy, patients with anaplastic thyroid cancer (ATC) are in desperate need of new therapeutic strategies. The objective of this study was to evaluate the effects of MLN8054, an inhibitor of the Aurora serine/threonine kinases, on ATC cells in vitro and on ATC xenografts as a new therapeutic strategy for ATC. Three anaplastic (Hth74, C643, Kat4) and one follicular (FTC133) thyroid cancer cell lines were evaluated in vitro and Kat4 xenografts in vivo. The antiproliferative effect of MLN8054 (0.1–10 μM) on thyroid cancer cells was quantified by sulphorhodamine B‐assay. The proapoptotic effect and the effects on the cell cycle were evaluated by flow cytometry after Annexin‐V‐FITC staining. Further Histone H3 phosphorylation was analysed. In vivo, antiproliferative and antiangiogenic effects were assessed by tumor volume and morphometric analysis following immunohistochemical staining (Ki‐67, pHisH3, CD31). Treatment of the different TC cells with MLN8054 inhibited proliferation in a time‐ and dose‐dependent manner, with IC50 values between 0.1 and 10 μM. Administration of MLN8054 resulted in an increase of apoptotic cells, decreased Histone H3 phosphorylation and induced cell cycle arrest. In vivo, treatment of ATC by MLN8054 resulted in an up to 86% reduced tumor volume and 89% reduced tumor vascularity. In conclusion, our data demonstrated that Aurora kinase inhibition is effective in reducing cell growth and inducing apoptosis of ATC in vitro and tumor growth and vascularity in vivo. Controlled clinical studies on MLN8054 or comparable compounds would be worthwhile to evaluate its potential therapeutic value for treatment of ATC. (Cancer Sci 2011; 102: 762–768)

Incision and drainage preceding definite surgery achieves lower 20‐year long‐term recurrence rate in 583 primary pilonidal sinus surgery patients

Background: It has long been suspected that acute infection leads to less satisfactory results in soft tissue surgery. Its influence on long‐term recurrence rate in primary pilonidal sinus surgery has not been investigated yet.

Paneling human thyroid cancer cell lines for candidate proteins for targeted anti‐angiogenic therapy

Tumor angiogenesis is believed to result from an imbalance of pro‐ and anti‐angiogenic factors, some of which are candidates for targeted therapy. Such therapy has raised hopes for patients with undifferentiated thyroid carcinomas, who are facing a grave prognosis with a survival of only months. In this study, in vivo growth of xenografted human thyroid carcinomas unexpectedly responded quite differently to neutralizing anti‐vascular endothelial growth factor (VEGF) antibody. In particular, lasting inhibition as well as accelerated growth occurred after treatment. Consequently, a panel of anti‐angiogenic factors was addressed in a representative sample of thyroid carcinoma lines. VEGF, fibroblast growth factor (FGF‐2), and endostatin were demonstrated by Western blotting and EIA, whereas PDGF‐A, PDGF‐B, and IL‐6 were negative. Quantification of VEGF, FGF‐2, and endostatin revealed a wide range of concentrations from 500 to 4,200 pg/ml VEGF, 5 to 60 pg/ml FGF‐2, and 50 to 300 pg/ml endostatin, not related to a particular histologic thyroid carcinoma background. Angiostatin (kringles 1–3) was detected in all, but one of the cell lines. Finally, aaATIII was confirmed in FTC133 cells. These data highlight the complex regulation of angiogenesis in thyroid carcinoma cell lines and suggest that the array of angiogenic factors differs markedly between individual cell lines. For the first time, angiostatin, endostatin, and possibly also aaATIII are identified as novel candidate regulators of angiogenesis in thyroid carcinoma cells. J. Cell. Biochem. 98: 954–965, 2006.

Functional thyrotropin receptor attenuates malignant phenotype of follicular thyroid cancer cells

Thyrotropin (TSH) is a thyroid-specific growth factor inducing differentiated function and growth of thyrocytes in vitro. In thyroid cancer, loss of TSH-receptor (TSHR) expression is a sign of de-differentiation and is believed to contribute to the malignant phenotype. The present studies aimed to determine the in vitro and in vivo effects of functioning tSHR in the follicular thyroid cancer cell line HTC, a subclone of FTC133 cells, lacking endogenous expression of TSHR, and HTCtshr+cells transfected with human TSHR-cDNA. HTCtshr+cells grew faster in vitro (doubling time 1.15 vs 1.56 d, p<0.05) and TSH caused a dose-dependent growth response. Adhesion to and invasion through reconstituted basement membrane were reduced in HTCtshr+cells, but when stimulated with TSH increased to levels comparable to naïve HTC cells. In vivo, tumor latency was 11 d for naïve HTC as compared to 21 d for HTCtshr+xenografts. Smaller tumor volumes were registered for HTCtshr+cells (250±217 vs 869±427 mm3, p<0.05). Angiogenesis, as determined by vascular surface density density (VSD) of experimental tumors, was enhanced in naïve HTC tumors (VSD 0.87±0.1 μm−1 vs 0.55±0.2μm−1 in HTCtshr+, p<0.05). VEGF secretion was more pronounced in naïve HTC cells stimulated with EGF, than in HTCtshr+cells stimulated with either TSH or EGF. In conclusion, regained expression of functional TSHR in the follicular thyroid cancer cell line HTC alters in vitro features commonly associated with the malignant phenotype. Smaller tumors and reduced angiogenesis of xenotransplanted HTC cells with functioning TSHR suggest a less aggressive in vivo phenotype. The present data highlight the pivotal role of TSHR to affect transformed thyrocytes in vitro and in vivo. They also suggest a role for EGF as a modulator of angiogenesis in thyrocytes devoid of TSHR.

Combined inhibition of cellular pathways as a future therapeutic option in fatal anaplastic thyroid cancer

Conventional treatment by surgery, radioiodine, and thyroxin-suppressive therapy often fails to cure anaplastic thyroid cancer (ATC). Therefore several attempts have been made to evaluate new therapy options by use of “small molecule inhibitors”. ATC was shown to respond to monotherapeutic proteasome and Aurora kinase inhibition in vitro as well as in xenotransplanted tumor cells. Aim of this study was to evaluate the effect of combined treatment targeting the ubiquitin–proteasome system by bortezomib and Aurora kinases by use of MLN8054. Three ATC cell lines (Hth74, C643, and Kat4.1) were used. The antiproliferative effect of combined treatment with bortezomib and MLN8054 was assessed by MTT-assay and cell cycle analysis (FACS). Proapoptotic effects were evaluated by measurement of Caspase-3 activity, and effects on VEGF secretion were analyzed by ELISA. Compared to mono-application combined treatment with bortezomib and MLN8054 resulted in a further decrease of cell density, whereas antagonizing effects were found regarding cell cycle progression. Caspase-3 activity was increased up to 2.7- and 14-fold by mono-application of MLN8054 and bortezomib, respectively. When the two drugs were used in combination, a further enhancement of Caspase-3 activity was achieved, depending on the cell line. VEGF secretion was decreased following bortezomib treatment and remained unchanged by MLN8054. Only in C643 cells, the bortezomib-induced down-regulation was enhanced when MLN8054 was applied simultaneously. In conclusion, our data demonstrate that targeting the proteasome and Aurora kinases simultaneously results in additional antitumoral effects in vitro, especially regarding cell growth and induction of apoptosis. The efficacy of this therapeutic approach remains to be revised by in vivo and clinical application.

Targeting the Proteasome as a Promising Therapeutic Strategy in Thyroid Cancer

Targeting the ubiquitin–proteasome system by using proteasome inhibitors represents a novel approach for cancer therapy. Anaplastic thyroid cancer (ATC), a subtype of thyroid cancer (TC), fails to respond to conventional TC treatment. Here we investigated the effects of bortezomib on TC in vitro. Further, the study aimed to evaluate its potential for TC treatment in vivo.

Does gentamycin affect long term recurrence rate in pilonidal sinus surgery

SummaryBACKGROUND: The influence of topical intraoperative gentamycin on long term recurrence rate in primary pilonidal sinus surgery has not yet been investigated. METHODS: One hundred and eight-seven patients following excision of primary pilonidal sinus disease (PSD) and primary symmetrical midline closure were analysed regarding the use (group 1) or non-use (group 2) of topical application of an intraoperative gentamycin sponge after a median follow-up of 16 years by a specific questionnaire. RESULTS: The actuarial 15-year-recurrence rate in group 1 was 31% (34/111) compared to 26% (20/76) in group 2, which was statistically not different (p = 0.99). Recurrences occurred with a median 2.7 (range 0.1–20.1) years after primary surgery, so time to recurrence did not differ between both groups (4.3 ± 0.8 years group 1 vs. 6.8 ± 1.5 years group 2; p = 0.99). CONCLUSIONS: The suggested positive effects of topical gentamycin application on long term recurrence rate could not be confirmed. Astonishingly though, surgical infection does not seem to alter long term recurrence rate.

Strength of Occipital Hair as an Explanation for Pilonidal Sinus Disease Caused by Intruding Hair

BACKGROUND: Pilonidal sinus disease is thought to be caused by intrusion of hair into healthy skin; loose hair in the intergluteal fold is thought to promote disease. However, compelling evidence to support these postulates is lacking; the cause of pilonidal sinus disease remains uncertain. OBJECTIVE: To determine whether particular properties of hair are associated with susceptibility to pilonidal sinus disease, we compared physical properties of hairs of patients with pilonidal sinus disease with hairs from control subjects who were matched for sex, BMI, and age. DESIGN: This was an experimental study with establishment of a mechanical strength test for single hairs to quantify the maximum vertical force that a hair could exert, following tests of strength of occipital, lumbar, and intergluteal hair. SETTINGS: Hair from patients with pilonidal sinus disease and matched control subjects were harvested from patients of the St. Marienhospital Vechta Department of Procto-Surgery. PATIENTS: A total of 17 adult patients with pilonidal sinus disease and 217 control subjects were included. MAIN OUTCOME MEASURES: ANOVA and intraclass and interclass variations of data gained from mechanical strength tests of occipital, lumbar, and intergluteal hair were included. RESULTS: Vertical hair strength was significantly greater in patients with pilonidal sinus disease. Occipital hair exhibited 20% greater, glabella sacralis 1.1 times greater, and intergluteal hair 2 times greater strength in patients with pilonidal sinus disease than in matched control subjects (all p = 0.0001). In addition, patients with pilonidal sinus disease presented with significantly more hair at the glabella sacralis and in the intergluteal fold. LIMITATIONS: The study was limited by its relatively small number of patients from a specific cohort of European patients. CONCLUSIONS: Occipital hair exhibited considerable vertical strength. Because occipital hair exerted the greatest force and cut hair fragments were found in the pilonidal nest in large quantities, these data suggest that pilonidal sinus disease is promoted by occipital hair. See Video Abstract at http://links.lww.com/DCR/A435.