Rudy Van den Broecke

Comparison of closed-loop controlled administration of propofol using Bispectral Index as the controlled variable versus "standard practice" controlled administration.

BackgroundThis report describes a new closed-loop control system for propofol that uses the Bispectral Index (BIS) as the controlled variable in a patient-individualized, adaptive, model-based control system, and compares this system with manually controlled administration of propofol using hemodynamic and somatic changes to guide anesthesia. MethodsTwenty female patients, American Society of Anesthesiologists physical status I or II, who were scheduled for gynecologic laparotomy were included to receive propofol–remifentanil anesthesia. In group I, propofol was titrated using a BIS-guided, model-based, closed-loop system. The BIS target was set at 50. In group II, propofol was titrated using classical hemodynamic signs of (in)adequate anesthesia. Performance of control during induction and maintenance of anesthesia were compared between both groups using BIS as the controlled variable in group I and the reference variable in group II, and, conversely, the systolic blood pressure as the controlled variable in group II and the reference variable in group I. At the end of anesthesia, recovery profiles between groups were compared. ResultsAlthough patients undergoing manual induction of anesthesia in group II at 300 ml/h reached a BIS level of 50 faster than patients undergoing open-loop, computer-controlled induction in group I, manual induction caused a more pronounced initial overshoot of the BIS target. This resulted in a more pronounced decrease in blood pressure in group II. During the maintenance phase, better control of BIS and systolic blood pressure was found in group I compared with group II. Recovery was faster in group I. ConclusionA closed-loop system for propofol administration using the BIS as a controlled variable together with a model-based controller is clinically acceptable during general anesthesia.

Effect of the Secretory Small GTPase Rab27B on Breast Cancer Growth, Invasion, and Metastasis

BACKGROUND Secretory GTPases like Rab27B control vesicle exocytosis and deliver critical proinvasive growth regulators into the tumor microenvironment. The expression and role of Rab27B in breast cancer were unknown. METHODS Expression of green fluorescent protein (GFP) fused with wild-type Rab3D, Rab27A, or Rab27B, or Rab27B point mutants defective in GTP/GDP binding or geranylgeranylation, or transient silencing RNA to the same proteins was used to study Rab27B in estrogen receptor (ER)-positive human breast cancer cell lines (MCF-7, T47D, and ZR75.1). Cell cycle progression was evaluated by flow cytometry, western blotting, and measurement of cell proliferation rates, and invasion was assessed using Matrigel and native type I collagen substrates. Orthotopic tumor growth, local invasion, and metastasis were analyzed in mouse xenograft models. Mass spectrometry identified proinvasive growth regulators that were secreted in the presence of Rab27B. Rab27B protein levels were evaluated by immunohistochemistry in 59 clinical breast cancer specimens, and Rab3D, Rab27A, and Rab27B mRNA levels were analyzed by quantitative real-time polymerase chain reaction in 20 specimens. Statistical tests were two-sided. RESULTS Increased expression of Rab27B promoted G(1) to S phase cell cycle transition, proliferation and invasiveness of cells in culture, and invasive tumor growth and hemorrhagic ascites production in a xenograft mouse model (n = 10; at 10 weeks, survival of MCF-7 GFP- vs GFP-Rab27B-injected mice was 100% vs 62.5%, hazard ratio = 0.26, 95% confidence interval = 0.08 to 0.88, P = .03). Mass spectrometric analysis of purified Rab27B-secretory vesicles identified heat-shock protein 90alpha as key proinvasive growth regulator. Heat-shock protein 90alpha secretion was Rab27B-dependent and was required for matrix metalloproteinase-2 activation. All Rab27B-mediated functional responses were GTP- and geranylgeranyl-dependent. Presence of endogenous Rab27B mRNA and protein, but not of Rab3D or Rab27A mRNA, was associated with lymph node metastasis (P < .001) and differentiation grade (P = .001) in ER-positive human breast tumors. CONCLUSIONS Rab27B regulates invasive growth and metastasis in ER-positive breast cancer cell lines, and increased expression is associated with poor prognosis in humans.

Follicular growth in fresh and cryopreserved human ovarian cortical grafts transplanted to immunodeficient mice

OBJECTIVE To investigate follicle growth in fresh and cryopreserved human ovarian cortical grafts transplanted to immunodeficient mice. STUDY DESIGN Fresh or frozen-thawed human ovarian cortex was grafted subcutaneously or under the kidney capsule of 43 mice (35 nude mice and eight SCID mice), 14 of which were non-stimulated controls, 21 injected intra-peritoneally with gonadotrophins during 2 weeks and eight injected during 3 months. Follicle count was compared by Chi-square. RESULTS Proportions of primordial follicles were significantly lower in grafts than in the tissue before transplantation in gonadotrophin-stimulated mice (37% versus 79%), but not in non-stimulated mice (51% versus 74%). Proportions of primary and secondary follicles were increased after transplantation indicating early follicular growth. One antral follicle was observed in a graft in a mouse stimulated for 3 months. CONCLUSION Primordial follicles in fresh or frozen-thawed human ovarian cortex transplanted under the kidney capsule or subcutaneously can grow and are responsive to hormonal stimulation. CONDENSATION Primordial follicles in fresh and cryopreserved human ovarian cortical grafts can initiate growth after transplantation to immunodeficient mice

Maturation of Mouse Primordial Follicles by Combination of Graftingand In Vitro Culture

Abstract Cryopreservation of ovarian cortical tissue and subsequent transplantation or in vitro culture of follicles are technologies under development with the aim to safeguard fertility in patients with gonadal failure. In the present study, we investigated whether primordial follicles could be triggered to full maturation by a combination of in vivo transplantation and in vitro culture in a mouse model. In a first step, newborn mouse ovaries containing only primordial follicles were allotransplanted under the renal capsule of ovariectomized recipient mice. The second step was to mechanically isolate growing preantral follicles from the graft and culture these in vitro to maturity. In our experiment, one newborn mouse ovary was transplanted under the renal capsule of each 8- to 12-wk-old F1 (C57Bl/6j × CBA/Ca) female ovariectomized recipient (n = 26). Two weeks after transplantation, all 26 grafts were recovered. Four grafts were processed for histology and showed that developmental stages of follicles in 14-day-old ovarian grafts were comparable to those in 14-day-old mouse ovaries. The 22 remaining grafts were used for mechanical isolation of preantral follicles. As a control group, preantral follicles isolated from ovaries of 14-day-old mice were used. The mean preantral follicle yield per ovary was 11 in the transplant group versus 33 in the control group. Follicles were cultured individually in 20-μl droplets of α-MEM supplemented with 100 mIU rFSH and 5% fetal bovine serum for 12 days under an atmosphere of 5% CO2 in air at 37°C. By Day 12 of culture, 66.5% of follicles retained their oocytes in the grafting group versus 97.5% in the control group (P < 0.001). Final oocyte maturation was induced by addition of 2.5 IU/ml hCG. At 14–16 h post-HCG, the percentages of oocytes showing germinal vesicle breakdown and polar body extrusion were significantly higher in the control group (90.6% and 82.8%) compared to the grafting group (60% and 45%). The mean diameter of the mature oocytes of the grafting group (69.9 ± 4.45 μm) was similar to that of oocytes from the control group (70.5 ± 2.35 μm). Our results suggest that maturation of mouse primordial follicles is feasible by combination of in vivo transplantation and in vitro culture. This two-step strategy may be an attractive model for promoting the growth and maturation of primordial follicles from other species.

Polymorphisms in nonhomologous end‐joining genes associated with breast cancer risk and chromosomal radiosensitivity

As enhanced chromosomal radiosensitivity (CRS) results from non‐ or misrepaired double strand breaks (DSBs) and is a hallmark for breast cancer and single nucleotide polymorphisms (SNPs) in DSB repair genes, such as non homologous end‐joining (NHEJ) genes, could be involved in CRS and genetic predisposition to breast cancer. In this study, we investigated the association of five SNPs in three different NHEJ genes with breast cancer in a population‐based case‐control setting. The total patient population composed of a selected group of patients with a family history of the disease and an unselected group, consisting mainly of sporadic cases. SNP analysis showed that the c.2099‐2408G>A SNP (XRCC6) has a significant, positive odds ratio (OR) of 2.81 (95% confidence interval (CI): 1.30–6.05) for the heterozygous (He) and homozygous variant (HV) genotypes in the selected patient group. For the c.‐1310 C>G SNP (XRCC5) a significant OR of 1.85 (95%CI: 1.01–3.41) was found for the He genotype in the unselected patient group. On the contrary, the HV genotype of c.1781G>T (XRCC5) displays a significant, negative OR of 0.43 (95%CI: 0.18–0.99) in the total patient population. The He+HV genotypes of the c.2099‐2408G>A SNP (XRCC6) also showed high and significant ORs in the group of “radiosensitive,” familial breast cancer patients. In conclusion, our results provide preliminary evidence that the variant allele of c.‐1310C>G (XRCC5) and c.2099‐2408G>A (XRCC6) are risk alleles for breast cancer as well as CRS. The HV genotype of c.1781G>T (XRCC5) on the contrary, seems to protect against breast cancer and ionizing radiation induced micronuclei.

Hypofractionated whole breast irradiation for patients with large breasts: A randomized trial comparing prone and supine positions

BACKGROUND AND PURPOSE Comparison of acute toxicity of whole-breast irradiation (WBI) in prone and supine positions. MATERIALS AND METHODS This non-blinded, randomized, prospective, mono-centric trial was undertaken between December 29, 2010, and December 12, 2012. One hundred patients with large breasts were randomized between supine multi beam (MB) and prone tangential field (TF) intensity modulated radiotherapy (IMRT). Dose-volume parameters were assessed for the breast, heart, left anterior descending coronary artery (LAD), ipsilateral lung and contralateral breast. The primary endpoint was acute moist skin desquamation. Secondary endpoints were dermatitis, edema, pruritus and pain. RESULTS Prone treatment resulted in: improved dose coverage (p<0.001); better homogeneity (p<0.001); less volumes of over-dosage (p=0.001); reduced acute skin desquamation (p<0.001); a 3-fold decrease of moist desquamation p=0.04 (chi-square), p=0.07 (Fishers exact test)); lower incidence of dermatitis (p<0.001), edema (p=0.005), pruritus (p=0.06) and pain (p=0.06); 2- to 4-fold reduction of grades 2-3 toxicity; lower ipsilateral lung (p<0.001) and mean LAD (p=0.007) dose; lower, though statistically non-significant heart and maximum LAD. CONCLUSIONS This study provides level I evidence for replacing the supine standard treatment by prone IMRT for whole-breast irradiation in patients with large breasts. A confirmatory trial in a multi-institutional setting is warranted.

Use of Tamoxifen Before and During Pregnancy

For premenopausal patients with receptor-positive early breast cancer, administration of tamoxifen for 5 years constitutes the main adjuvant endocrine therapy. During pregnancy, tamoxifen and its metabolites interact with rapidly growing and developing embryonic or fetal tissues. Information about tamoxifen and pregnancy was gathered by searching PubMed. In addition, we had access to the records of the pharmaceutical company AstraZeneca. Because these observations are retrospective and other therapies and diagnostic measures are possible confounders, a causal relationship was not established between tamoxifen treatment and pregnancy outcome. The records from AstraZeneca documented three live births with congenital anomalies and four live births without congenital anomalies related to tamoxifen treatment before pregnancy. Tamoxifen therapy during pregnancy resulted in 16 live births with congenital malformations and a total of 122 live births without malformations. The 122 live births without malformations included 85 patients from a prevention trial that did not record a single anomaly, whereas the AstraZeneca Safety Database alone reported 11 babies with congenital malformations of 44 live births. Additionally, there were: 12 spontaneous abortions, 17 terminations of pregnancy without known fetal defects, six terminations of pregnancy with fetal defects, one stillbirth without fetal defects, two stillbirths with fetal defects, and 57 unknown outcomes. The relatively high frequency of severe congenital abnormalities indicates that reliable birth control during tamoxifen treatment is mandatory. After tamoxifen use, a washout period of 2 months is advisable based on the known half-life of tamoxifen. In case of an inadvertent pregnancy, risks and options should be discussed.

Prognostic significance of oncogenic markers in ductal carcinoma in situ of the breast: a clinicopathologic study.

Abstract:  Ductal carcinoma in situ (DCIS) is a heterogeneous malignant condition of the breast with an excellent prognosis. Until recently mastectomy was the standard treatment. As the results of the National Surgical Adjuvant Breast and Bowel Project‐17 trial and the introduction of the Van Nuys Prognostic Index (VNPI) less radical therapies are used. Objectives are to identify clinicopathologic and biologic factors that may predict outcome. Cases of DCIS diagnosed in two Belgian University Centers were included. Paraffin‐embedded material and Hematoxylin and Eosin stained slides of DCIS cases were reviewed and tumor size, margin width, nuclear grade, and comedo necrosis were assessed. Molecular markers (estrogen receptor, progesterone receptor, HER1‐4, Ki67, and c‐myc) were assayed immunohistochemically. Applied treatment strategies were correlated with the prospective use of the VNPI score. Kaplan–Meier survival plots were generated with log‐rank significance and multiple regression analysis was carried out using Cox proportional hazards regression analysis; 159 patients were included with a median age of 54 years (range 29–78); 141 had DCIS and 18 DCIS with microinvasion. The median time of follow‐up was 54 months (range 5–253). Twenty‐three patients developed a recurrence (14.5%). The median time to recurrence was 46 months (range 5–253). Before the introduction of the VNPI, 37.5% of the DCIS patients showed a recurrence while thereafter 6.7% recurred (p < 0.005). Two recurrences occurred in the VNPI group I (7.1%); seven in the VNPI group II (8.5%) (median time to recurrence 66.3 months) and 14 in the VNPI group III (28.5%) (median time to recurrence 40.2 months) (disease‐free survival [DFS]: p < 0.05). A Cox proportional hazards regression analysis indicated that tumor size, margin width, pathologic class, and age were independent predictors of recurrence, but none of the studied molecular markers showed this. Overexpression of HER4 in the presence of HER3 was found to be associated with a better DFS (p < 0.05). This study confirms the value of the VNPI score and questions the benefit of an aggressive approach in the low‐risk DCIS lesions. Independent predictors for recurrence included size, margin width, pathologic class, and age, but none of the molecular markers were part of it. Overexpression of HER4 in the presence of HER3 was associated with a better DFS.

Cancer-associated adipose tissue promotes breast cancer progression by paracrine Oncostatin M and Jak/STAT3 signaling.

Increasing evidence supports the critical roles played by adipose tissue in breast cancer progression. Yet, the mediators and mechanisms are poorly understood. Here, we show that breast cancer-associated adipose tissue from freshly isolated tumors promotes F-actin remodeling, cellular scattering, invasiveness, and spheroid reorganization of cultured breast cancer cells. A combination of techniques, including transcriptomics, proteomics, and kinomics enabled us to identify paracrine secretion of oncostatin M (OSM) by cancer-associated adipose tissue. Specifically, OSM, expressed by CD45(+) leucocytes in the stromal vascular fraction, induced phosphorylation of STAT3 (pSTAT3-) Y705 and S727 in breast cancer cells and transcription of several STAT3-dependent genes, including S100 family members S100A7, S100A8, and S100A9. Autocrine activation of STAT3 in MCF-7 cells ectopically expressing OSM-induced cellular scattering and peritumoral neovascularization of orthotopic xenografts. Conversely, selective inhibition of OSM by neutralizing antibody and Jak family kinases by tofacitinib inhibited STAT3 signaling, peritumoral angiogenesis, and cellular scattering. Importantly, nuclear staining of pSTAT3-Y705 identified at the tumor invasion front in ductal breast carcinomas correlates with increased lymphovascular invasion. Our work reveals the potential of novel therapeutic strategies targeting the OSM and STAT3 axis in patients with breast cancer harboring nuclear pSTAT3-Y705.

Vacuolar H+ ATPase expression and activity is required for Rab27B-dependent invasive growth and metastasis of breast cancer

The secretory Rab27B small GTPase promotes invasive growth and metastasis in estrogen receptor (ER) α‐positive breast cancer cells by orchestrating the peripheral targeting of vesicles secreting proinvasive growth regulators. Increased Rab27B expression is associated with poor prognosis in breast cancer patients. The molecular mechanisms of peripheral Rab27B secretory vesicle distribution are poorly understood. Mass spectrometry analysis on green fluorescent protein (GFP)‐Rab27B vesicles prepared from GFP‐Rab27B transfected MCF‐7 human breast cancer cells detected eight subunits of the vacuolar H(+)‐ATPase (V‐ATPase) and the presence of V0a1 and V0d1 subunits was confirmed by Western blot analysis. Reversible inhibition of V‐ATPase activity by bafilomycin A1 or transient silencing of V0a1 or V0d1 subunits demonstrated that V‐ATPase controls peripheral localization and size of Rab27B vesicles. V‐ATPase expression and activity further controls Rab27B‐induced collagen type I invasion, cell‐cycle progression and invasive growth in the chorioallantoic membrane assay. In agreement, Rab27B‐dependent extracellular heat shock protein90α release and matrix metalloprotease‐2 activation is markedly reduced by bafilomycin A1 and transient silencing of V0a1 and V0d1 subunits. Poor prognosis ERα‐positive primary breast tumors expressing high levels of Rab27B also expressed multiple V‐ATPase subunits and showed a strong cytoplasmic and peripheral V‐ATPase V1E expression. In conclusion, inhibiting V‐ATPase activity by interfering agents and drugs might be an effective strategy for blocking Rab27B‐dependent proinvasive secretory vesicle trafficking in ERα‐positive breast cancer patients.