Godelieve Verbist

Fate of collagen-based implants used in pelvic floor surgery: A 2-year follow-up study in a rabbit model

OBJECTIVE The purpose of this study was to compare the long-term host response to 2 different collagen matrices versus macroporous polypropylene mesh. STUDY DESIGN Four full-thickness abdominal wall defects in 35 rabbits were reconstructed with either polypropylene (Prolene), porcine dermal (Pelvicol), or small intestine submucosal collagen matrix (SIS). Animals were sacrificed on day 30, 60, 90, 180, 365, 540, and 720 days to evaluate morphologic and biomechanical properties of explants. RESULTS Prolene provoked a fibrotic reaction within 30 days. SIS was entirely replaced by a thin fibrotic layer within 60 days. Pelvicol was encapsulated, remaining structurally unchanged up to 180 days. Thereafter, half underwent degradation by a foreign body reaction. CONCLUSION Prolene was integrated by an increasingly organised fibrotic scar while SIS was entirely remodelled within 60 days. Pelvicol implants underwent late onset (> or = 180 days) degradation. After 2 years of implantation there were no differences in tensiometric strength between the 3 different materials.

Enrichment of collagen plugs with platelets and amniotic fluid cells increases cell proliferation in sealed iatrogenic membrane defects in the foetal rabbit model

The purpose of this study was to evaluate cell proliferation in platelet‐enriched collagen plugs with and without addition of amniotic fluid‐derived heterologous foetal cells to seal an iatrogenic membrane defect in the foetal rabbit model.

Wilms tumor gene 1 (WT1) is a prognostic marker in high-grade uterine sarcoma.

Introduction: Wilms tumor gene 1 (WT1) contributes to uterine sarcoma tumor biology. In this study, we aimed to clarify the prognostic value of WT1. Methods: A retrospective clinical and histopathological review of 71 women with high-grade uterine sarcoma (leiomyosarcoma [n = 24], undifferentiated sarcoma [n = 9]), and carcinosarcoma (n = 38) was performed. Patients were followed up for at least 12 months. Wilms tumor gene 1 expression was determined by immunohistochemistry. Data on recurrence (progression-free survival) and overall survival (OS) were available for all patients. Univariate and multivariate analyses of WT1 expression were carried out using Kaplan-Meier curves and Cox regression, respectively. Results: Forty-nine (69%) tumors were WT1 positive. Forty-seven (66%) patients died of the disease, with a median OS time of 22 months. Wilms tumor gene 1 was a predictor of survival in the univariate analysis: the hazard ratio of WT1 positivity was 2.44 (95% confidence interval, 1.34-4.71) for progression-free survival and 2.48 (95% confidence interval, 1.26-4.90) for OS. Multivariate analysis including stage, age, tumor size, and sarcoma subtype identified only stage and WT1 positivity as independent prognostic markers for survival. Conclusions: The identification of WT1 as a prognostic marker confirms its role in high-grade uterine sarcoma and carcinosarcoma tumor biology.

The use of lymph vessel markers to predict endometrial cancer outcome.

Objective: To evaluate lymphangiogenesis and lymph vessel space involvement in different subsets of endometrial cancer using podoplanin, a specific marker for lymphatic endothelium. Methods: Sixty-two patients undergoing a hysterectomy with lymphadenectomy were included. Distribution of histopathologic subtypes was as follows: 30 endometrioid (48%), 18 serous (29%), 9 clear cell carcinoma (15%), and 5 carcinosarcomas (8%). Distribution of surgical stage according to the International Federation of Gynecology and Obstetrics 2009 criteria was as follows: 33 stage I (53%), 7 stage II (11%), 1 stage IIIA (2%), 15 stage IIIC1 (24%), and 6 stage IIIC2 (10%). Tumor samples were immunostained for podoplanin and the panendothelial marker, CD31. Peritumoral and intratumoral blood vessel density and lymph vessel density were assessed using an image analysis system that calculated mean vessel cross-sectional area (in micrometer squared) and vessel density (per millimeter squared). Presence of blood vessel space involvement and lymph vessel space involvement was screened for. The findings were linked with clinical outcome using Cox regression. Results: Twenty-one patients (34%) experienced recurrence, and 13 (21%) died of disease. Univariate analysis showed that blood vessel space involvement was related to worse overall survival (hazard ratio, 6.59; 95% confidence interval, 1.30-120). Multivariate analyses confirmed the prognostic importance of this variable for overall survival (hazard ratio, 7.52; 95% confidence interval, 1.32-144). Conclusion: Blood vessel space involvement is a prognostic marker for worse survival. Although lymph vessels were stained with the most reliable marker, podoplanin, lymph vessel density and lymphovascular space involvement do not seem to be of prognostic importance.

Tensile strength and host response towards silk and type I polypropylene implants used for augmentation of fascial repair in a rat model

Objective: We compared host response, architectural integration and tensile strength of two different macroporous silk constructs to a polypropylene type I implant in a rat model for augmentation of primary fascial defect repair. Materials and Methods: Animals were sacrificed on days 7, 14, 30 and 90 after implantation. The explants were evaluated macroscopically for infections, herniations and adhesions, mechanically for tensile strength, and histopathologically, to evaluate collagen deposition and inflammatory response. Results: The tensile strength of the explants showed a gradual increase for all materials. All implants uniformly shrank around one fifth by 90 days. In the silk implants, the inflammatory reaction showed a remarkable higher number of foreign body giant cells that characteristically spread from the periphery into implants. Collagen deposition was comparable for all the materials. In Silk a higher grade of neovascularisation was observed. Conclusion: Silk explants expressed high tensiometric strength, which was associated with a marked fibrotic process. The silk implants induced a strong foreign body reaction accompanied by microscopic signs of architectural degradation at 90 days. Polypropylene explants showed a more moderate foreign body reaction without architectural disturbance.

A Comparative Study on Culture Conditions and Routine Expansion of Amniotic Fluid-Derived Mesenchymal Progenitor Cells

Background: Amniotic fluid (AF) cell populations will be applied in perinatology. We aimed to test the feasibility of large-scale cell expansion. Study Methods: We determined the best out of three published expansion protocols for mesenchymal progenitors (AF samples, n = 4) in terms of self-renewal ability. Characterization was performed based on morphology, surface marker analysis, cytogenetic stability, and differentiation potential. The conditions for the best self-renewal ability were further determined in a consecutive series (n = 159). Results: The medium containing fetal bovine serum (FBS), epidermal growth factor, insulin, transferrin, and tri-iodothyronine, combined with seeding on gelatin-coated wells, best stimulated the growth of cells with mesenchymal features, as demonstrated by flow cytometry; however, only osteogenic differentiation was possible. Large-scale testing (n = 44) failed to confirm a robust self-renewal ability. Better results were obtained (n = 88) using optimized FBS or an increased initial cell density. Eventually over 81% of cultures continued growing after the initial medium change and had mesenchymal features but failed differentiation assays. Discussion: Routine in vitro expansion of AF-derived mesenchymal cells remains problematic. Despite an increase in successful cell cultures from 40 up to 80% using optimized serum and an increased cell density, eventually cells failed to demonstrate differentiation abilities. Routine isolation and expansion from unselected AF samples remains a challenge.

Increased Expression of the Neuroregenerative Peptide Galanin in the Major Pelvic Ganglion Following Cavernous Nerve Injury

INTRODUCTION Erectile dysfunction (ED) remains a frequent complication of radical prostatectomy due to injury to the cavernous nerves (CNs). A recent microarray showed the neuropeptide galanin to be one of the most strikingly upregulated genes in the rat major pelvic ganglion (MPG) after bilateral CN crush injury (BCNI). AIM The aim of this study is to evaluate the temporal regulation of galanin in the MPG after BCNI and its relationship to functional nerve regeneration. METHODS Changes in galanin, galanin receptor (galR), and c-JUN mRNA expression were assessed in Sprague-Dawley rats after sham operation (n = 10) and at 48 hours (n = 10), 7 (n = 10), 14 (n = 5), 21 (n = 5), 30 (n = 5), and 60 (n = 5) days after BCNI using quantitative PCR. Erectile function was assessed by measuring intracavernous pressure (ICP) divided by mean arterial pressure (MAP) during CN electrostimulation. Immunohistochemistry was performed on the MPG in sham-operated animals and 5 days after BCNI. MAIN OUTCOME MEASURES ICP/MAP upon CN stimulation; galanin, galR1, -2, -3, and c-JUN mRNA expression at various time points after BCNI; and nNOS, galanin, and galR distribution in the MPG of sham-operated rats and after BCNI. RESULTS After BCNI, ICP/MAP values quickly deteriorate, while after 60 days, spontaneous restoration of erectile responses to CN stimulation is observed, reflecting CN regeneration. Galanin mRNA in the MPG is up to 186-fold upregulated compared with sham-operated rats at 48 hours and 7 days after BCNI and gradually declines with increasing time from injury, whereas galanin receptor expressions decrease and c-JUN gradually increases. Galanin expression shows a strong inverse correlation with erectile responses to CN stimulation with time from injury. Injured MPGs show a colocalization between galanin- and nNOS-positive neuronal cell population in the MPG. CONCLUSIONS Galanin is upregulated in the MPG in the early phase after CN injury after which it gradually decreases and is present in nNOS-positive neurons of the ganglion. We hypothesize that galanin upregulation is an important factor in the endogenous neuroregenerative response to CN injury.

Expression of ERCC1, p53, and class III β-tubulin do not reveal chemoresistance in endometrial cancer: results from an immunohistochemical study.

Background: In non-small cell lung cancer, expression of excision repair cross-complementation group 1 (ERCC1) and p53 correlates with platinum resistance and class III &bgr;-tubulin with resistance to taxanes. The potential to personalize treatment in endometrial cancer remains uninvestigated. Methods: Patients received platinum-based chemotherapy, with or without paclitaxel. Patients were divided into 2 groups: group A (n = 33) consisted of patients with early-stage endometrial cancer treated with adjuvant chemotherapy. Group B (n = 116) included cases with primary advanced or recurrent disease. Immunohistochemistry was performed to analyze the expression of ERCC1 and p53, for all cases, and class III &bgr;-tubulin for cases treated with paclitaxel. The findings were correlated with response according to Response Criteria in Solid Tumors; recurrence-free, disease-specific survival; and established prognostic markers. Results: The mean age of 149 patients was 64 years (range, 31-84 years). Distribution of histopathologic subtypes was as follows: 44 endometrioid (30%), 92 serous/clear cell (62%), and 13 carcinosarcomas (8%). In group A, 11 (33%) and 19 patients (58%) showed expression for ERCC1 and p53, respectively. Seven (78%) of nine patients receiving paclitaxel were positive for class III &bgr;-tubulin. There was no correlation between expression of ERCC1, p53, or class III &bgr;-tubulin and recurrence or survival. In group B, 25 (22%) and 61 patients (64%) were positive for ERCC1 and p53, respectively. Fifty-two (74%) of seventy patients receiving paclitaxel were positive for class III &bgr;-tubulin. Only p53 expression correlated with survival (P = 0.01). Conclusions: In contrast to theoretical assumptions, the current study did not reveal evidence that the expression of ERCC1 and class III &bgr;-tubulin predicts response to cytotoxic treatment and patient outcome in endometrial cancer.

Potential Targets' Analysis Reveals Dual PI3K/mTOR Pathway Inhibition as a Promising Therapeutic Strategy for Uterine Leiomyosarcomas-an ENITEC Group Initiative

Purpose: Uterine sarcomas are rare and heterogeneous tumors characterized by an aggressive clinical behavior. Their high rates of recurrence and mortality point to the urgent need for novel targeted therapies and alternative treatment strategies. However, no molecular prognostic or predictive biomarkers are available so far to guide choice and modality of treatment. Experimental Design: We investigated the expression of several druggable targets (phospho-S6S240 ribosomal protein, PTEN, PDGFR-α, ERBB2, and EGFR) in a large cohort of human uterine sarcoma samples (288), including leiomyosarcomas, low-grade and high-grade endometrial stromal sarcomas, undifferentiated uterine sarcomas, and adenosarcomas, together with 15 smooth muscle tumors of uncertain malignant potential (STUMP), 52 benign uterine stromal tumors, and 41 normal uterine tissues. The potential therapeutic value of the most promising target, p-S6S240, was tested in patient-derived xenograft (PDX) leiomyosarcoma models. Results: In uterine sarcomas and STUMPs, S6S240 phosphorylation (reflecting mTOR pathway activation) was associated with higher grade (P = 0.001) and recurrence (P = 0.019), as shown by logistic regression. In addition, p-S6S240 correlated with shorter progression-free survival (P = 0.034). Treatment with a dual PI3K/mTOR inhibitor significantly reduced tumor growth in 4 of 5 leiomyosarcoma PDX models (with tumor shrinkage in 2 models). Remarkably, the 4 responding models showed basal p-S6S240 expression, whereas the nonresponding model was scored as negative, suggesting a role for p-S6S240 in response prediction to PI3K/mTOR inhibition. Conclusions: Dual PI3K/mTOR inhibition represents an effective therapeutic strategy in uterine leiomyosarcoma, and p-S6S240 expression is a potential predictive biomarker for response to treatment. Clin Cancer Res; 23(5); 1274–85. ©2017 AACR.

In Vitro Validation of Survivin as Target Tumor-associated Antigen for Immunotherapy in Uterine Cancer.

Survivin is an antiapoptotic protein, not expressed in terminally differentiated adult tissues, yet overexpressed in several tumors. Therefore, it is an interesting target for immunotherapeutic strategies. In addition to specific overexpression in tumors, tumor survival is mediated by survivin and hence, tumor survival can be tackled by targeting survivin. Survivin expression in uterine cancer was validated by quantitative real-time polymerase chain reaction and immunohistochemistry. In addition, we evaluated survivin immunogenicity by analyzing spontaneous B-cell and T-cell responses in patients. Survivin as a protein was expressed in only a minority of normal tissues, whereas it was being expressed in all of the currently analyzed uterine cancers, both endometrial carcinoma (n=52) and uterine sarcoma (n=52). Survivin RNA transcripts were overexpressed in more aggressive tumors and survivin protein was overexpressed in recurrent endometrial tumors compared with primary tumors. Spontaneous T-cell responses were seen in 10/39 endometrial cancer patients and 3/16 uterine sarcoma patients. In normal controls, T-cell responses were found only in 1 donor (n=21). Although increased antibody titers were found in more aggressive and far-advanced tumors, no differences in B-cell responses were seen. Overall, when compared with normal controls, a B-cell response was only measured in 1/41 uterine sarcoma patients. In conclusion, we currently validated the presence of survivin in uterine cancer. In addition, spontaneous T-cell responses were found in 23.6% of the total patient population. These data indicate that a survivin-specific immune response may be induced spontaneously in patients, further fortifying the eligibility of survivin as an immunotherapeutic target.