Bidirectional transfer study of polystyrene nanoparticles across the placental barrier in an ex vivo human placental perfusion model

BACKGROUND: Nanoparticle exposure in utero might not be a major concern yet, but it could become more important with the increasing application of nanomaterials in consumer and medical products. Several epidemiologic and in vitro studies have shown that nanoparticles can have potential toxic effects. However, nanoparticles also offer the opportunity to develop new therapeutic strategies to treat specifically either the pregnant mother or the fetus. Previous studies mainly addressed whether nanoparticles are able to cross the placental barrier. However, the transport mechanisms underlying nanoparticle translocation across the placenta are still unknown. OBJECTIVES: In this study we examined which transport mechanisms underlie the placental transfer of nanoparticles. METHODS: We used the ex vivo human placental perfusion model to analyze the bidirectional transfer of plain and carboxylate modified polystyrene particles in a size range between 50 and 300 nm. RESULTS: We observed that the transport of polystyrene particles in the fetal to maternal direction was significantly higher than for the maternal to fetal direction. Regardless of their ability to cross the placental barrier and the direction of perfusion, all polystyrene particles accumulated in the syncytiotrophoblast of the placental tissue. CONCLUSIONS: Our results indicate that the syncytiotrophoblast is the key player in regulating nanoparticle transport across the human placenta. The main mechanism underlying this translocation is not based on passive diffusion, but is likely to involve an active, energy-dependent transport pathway. These findings will be important for reproductive toxicology as well as for pharmaceutical engineering of new drug carriers. CITATION: Grafmueller S, Manser P, Diener L, Diener PA, Maeder-Althaus X, Maurizi L, Jochum W, Krug HF, Buerki-Thurnherr T, von Mandach U, Wick P. 2015. Bidirectional transfer study of polystyrene nanoparticles across the placental barrier in an ex vivo human placental perfusion model. Environ Health Perspect 123:1280-1286; http://dx.doi.org/10.1289/ehp.1409271

Metachronous Primary Adenocarcinoma of Distal and Proximal Ureter within Two Years

Primary adenocarcinoma of the upper urinary tract, particularly of the ureter, is an extremely rare entity. We are reporting on the first case of metachronous appearance in one patient. The 71-year-old man underwent partial ureterectomy (R0 resection) for primary adenocarcinoma of the left distal ureter. 3 years later, nephroureterectomy had to be performed because of metachronous primary adenocarcinoma of the left proximal ureter. Extensive examinations revealed no evidence for further malignancies at both times. Primary adenocarcinoma of the upper urinary tract is rare but should be kept in mind, especially in patients with chronic inflammation and urinary tract obstruction. Due to the low incidence, there is a lack of data regarding its pathogenesis, diagnosis, and optimal treatment

Transfer studies of polystyrene nanoparticles in the ex vivo human placenta perfusion model: key sources of artifacts

International audienceNanotechnology is a rapidly expanding and highly promising new technology with many different fields of application. Consequently, the investigation of engineered nanoparticles in biological systems is steadily increasing. Questions about the safety of such engineered nanoparticles are very important and the most critical subject with regard to the penetration of biological barriers allowing particle distribution throughout the human body. Such translocation studies are technically challenging and many issues have to be considered to obtain meaningful and comparable results. Here we report on the transfer of polystyrene nanoparticles across the human placenta using an ex vivo human placenta perfusion model. We provide an overview of several challenges that can potentially occur in any translocation study in relation to particle size distribution, functionalization and stability of labels. In conclusion, a careful assessment of nanoparticle properties in a physiologically relevant milieu is as challenging and important as the actual study of nanoparticle-cell interactions itself

Expression of epithelial cell adhesion molecule (EpCam) in renal epithelial tumors

EpCam is an epithelial adhesion molecule expressed in a broad range of carcinomas. Clinical trials with specific humanized anti-EpCam antibodies have shown promising results and have been inaugurated in renal cell carcinoma (RCC) therapy. To study the EpCam expression profile, primary renal cell neoplasms as well as corresponding metastases were evaluated by immunohistochemistry in tissue microarrays. EpCam expression in oncocytomas and chromophobe RCCs was determined on conventional large sections. Moderate or strong EpCam expression was found in eighteen percent of clear cell (n=147), 75% of chromophobe (n=12), and 55% of papillary RCCs (n=20), but not in oncocytomas (n=3). On large sections, 90% of chromophobe RCCs (n=20) showed a strong and homogeneous positivity, whereas oncocytomas (n=15) revealed EpCam positivity in single tumor cells or small clusters. Fourteen percent of RCC metastases (n=97) showed EpCam expression. Patients with EpCam expressing clear cell RCC showed a trend toward a better prognosis in a Cox regression analysis including stage, grade, and necrosis. The data suggest EpCam as a potential therapeutic target in a subset of patients with RCC. In addition, expression patterns of EpCam could become a helpful tool in the discrimination of chromophobe RCC and oncocytoma

Prostate stem cell antigen is a promising candidate for immunotherapy of advanced prostate cancer

Immunotherapy of prostate cancer (CaP) may be a promising novel treatment option for the management of advanced CaP. However, the lack of suitable tumor antigens remains a major obstacle for the rational design of vaccines. To characterize potential CaP antigens, we determined the mRNA expression of the prostate-specific genes C1, C2, C5, PAGE-1, and prostate stem cell antigen (PSCA) in hormone-refractory CaP, benign prostatic hyperplasia, CaP cell lines, and CaP specimens. Among these gene products, only expression of PSCA appears to be retained in the majority of advanced CaP samples, as shown by reverse transcription-PCR analyses. Peptide fragments of PSCA presented in the context of major histocompatibility molecules could serve as recognition targets for CD8 T cells, provided these lymphocytes were not clonally deleted or peripherally tolerized. Our goal was to determine whether the human T-cell repertoire could recognize PSCA-derived peptide epitopes in the context of a common class I allele, HLA-A0201. Of nine peptides that, according to HLA-A0201 binding motifs, were candidate ligands of A0201 class I molecules, three peptides were able to stabilize HLA-A0201 molecules on the cell surface. One of the latter peptides, encompassing amino acid residues 14-22, was capable of generating a PSCA-specific T-cell response in a human lymphocyte culture from a patient with metastatic CaP. PSCA-specific CTLs recognized peptide-pulsed targets as well as three prostate carcinoma lines in cytotoxicity assays, indicating that this peptide could be endogenously processed. In conclusion, our findings establish PSCA as a potential target for antigen-specific, T cell-based immunotherapy of prostate carcinoma

Automated immunofluorescence analysis defines microvessel area as a prognostic parameter in clear cell renal cell cancer

Microvessel density (MVD) has been reported to have prognostic relevance for clear cell renal cell carcinoma (ccRCC). However, this finding is controversial because of the difficulty of MVD evaluation in this complex vascularized tumor type. The present study evaluates the use of an automated quantitative analysis (AQUA) system for objective and reproducible determination of tumor vascularization in clear cell renal cell carcinoma (ccRCC). The AQUA system was applied to tissue microarrays with 284 primary ccRCC tumors. To determine angiogenesis in ccRCC, we created an epithelial/stromal mask consisting of CD10, epithelial membrane antigen, and vimentin to distinguish epithelial tumor cells from CD34-positive endothelial cells. Using immunofluorescence and computer-aided quantification of CD34 expression, we measured the relative microvessel area (MVA) and compared the MVA to the manually counted MVD. The MVA determined by AQUA in a test set with 209 ccRCCs ranged from 0% to 30.3% (mean +/- SD, 10.1% +/- 6.3%). The manually determined MVD ranged from 6 to 987 vessels/mm(2) (416.8 +/- 252.8 vessels/mm(2)). MVA and MVD were significantly correlated (P < .001). A larger MVA was associated with histologic grade (P < .001), tumor stage (P =.008), presence of metastasis (P = .005), presence of sarcomatoid areas (P < .001), and tumor-specific survival (P < .001). Using MVA as defined in the test set, all associations with clinical and pathologic parameters were confirmed in a second independent validation set. MVA determination by AQUA is an objective and reliable method to quantify tumor vascularization in ccRCC. A large MVA correlates with a high MVD and is associated with better patient prognosis