Activation of Signal Pathways of Apoptosis under Conditions of Prolonged ER-Stress Caused by Exposure of Mouse Testicular Teratoma Cells to Selenium-Containing Compounds.

Aim to study the molecular mechanisms of apoptotic death of mouse testicular teratocarcinoma cells (line F-9) under exposure to the widely used selenium-containing compounds with antitumor activity, sodium selenite and methylseleninic acid. Methods fluorescence microscopy, MTT assay, Western blotting. Results It was shown that sodium selenite at a concentration of 10 µM and methylseleninic acid at concentrations of 1 and 10 µM cause apoptosis-dependent death of F-9 cells, excluding necrotic death. Western blotting showed an increase in the expression of XBP1s when treating F-9 cells with 1 µM methylseleninic acid. Conclusions 10 µM methylseleninic acid leads to cell apoptosis, most likely by activation of the IRE1 signaling pathway under prolonged stress of the endoplasmic reticulum.

Inducible histone K-to-M mutations are dynamic tools to probe the physiological role of site-specific histone methylation in vitro and in vivo.

Development and differentiation are associated with profound changes to histone modifications, yet their in vivo function remains incompletely understood. Here, we generated mouse models expressing inducible histone H3 lysine-to-methionine (K-to-M) mutants, which globally inhibit methylation at specific sites. Mice expressing H3K36M developed severe anaemia with arrested erythropoiesis, a marked haematopoietic stem cell defect, and rapid lethality. By contrast, mice expressing H3K9M survived up to a year and showed expansion of multipotent progenitors, aberrant lymphopoiesis and thrombocytosis. Additionally, some H3K9M mice succumbed to aggressive T cell leukaemia/lymphoma, while H3K36M mice exhibited differentiation defects in testis and intestine. Mechanistically, induction of either mutant reduced corresponding histone trimethylation patterns genome-wide and altered chromatin accessibility as well as gene expression landscapes. Strikingly, discontinuation of transgene expression largely restored differentiation programmes. Our work shows that individual chromatin modifications are required at several specific stages of differentiation and introduces powerful tools to interrogate their roles in vivo.

Direct Reprogramming of Human Neurons Identifies MARCKSL1 as a Pathogenic Mediator of Valproic Acid-Induced Teratogenicity.

Human pluripotent stem cells can be rapidly converted into functional neurons by ectopic expression of proneural transcription factors. Here we show that directly reprogrammed neurons, despite their rapid maturation kinetics, can model teratogenic mechanisms that specifically affect early neurodevelopment. We delineated distinct phases of in vitro maturation during reprogramming of human neurons and assessed the cellular phenotypes of valproic acid (VPA), a teratogenic drug. VPA exposure caused chronic impairment of dendritic morphology and functional properties of developing neurons, but not those of mature neurons. These pathogenic effects were associated with VPA-mediated inhibition of the histone deacetylase (HDAC) and glycogen synthase kinase-3 (GSK-3) pathways, which caused transcriptional downregulation of many genes, including MARCKSL1, an actin-stabilizing protein essential for dendritic morphogenesis and synapse maturation during early neurodevelopment. Our findings identify a developmentally restricted pathogenic mechanism of VPA and establish the use of reprogrammed neurons as an effective platform for modeling teratogenic pathways.

Leptin treatment of in vitro cultured embryos increases outgrowth rate of inner cell mass during embryonic stem cell derivation.

Leptin, a metabolic hormone, regulates the reproductive functions responding to both nutritional and body conditions. Embryonic stem cells play important roles in reproductive technology, but their derivation can be challenging. In this study, we evaluated the derivation rates of mouse embryonic stem cell (mESC) line from blastocysts developing in embryo culture media supplemented with different leptin concentrations. The results showed that addition of leptin into the embryo culture medium supported the in vitro development of mouse embryo. The mESC line derivation rates for media treated with 0, 10, 50, and 100 ng/ml of leptin were 61.24 % (54/88), 84.96 % (42/50), 81.79 % (61/76), and 85.78 % (56/67), respectively. In addition, leptin treatment of blastocysts upregulated the expression levels of the trophectoderm marker Cdx2, whereas inner cell mass markers Oct-4 and Nanog were not affected. mESC lines derived after leptin treatment demonstrated hallmarks of pluripotency, such as alkaline phosphatase activity, expression of, OCT4, NANOG, and SSEA1, as well as the ability to form embryoid bodies and well-differentiated teratomas. In conclusion, leptin has a positive effect on the derivation rate of mouse embryonic stem cell lines which may be, in part, due to its effects on the development of the trophectoderm cell lineage in the embryo.

Assessment of the carcinogenic effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin using mouse embryonic stem cells to form teratoma in vivo.

As the most toxic dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has gained lots of concerns, due to its diverse deleterious effects. However, the knowledge on carcinogenic risk of TCDD during early stage of development remains scarce. The in vivo teratoma formation model based on the transplantation of embryonic stem cells (ESCs) in immunodeficient mice is appealing for studying pluripotency and tumorigenicity in developmental biology, and also shows promise in environmental toxicology, especially in carcinogenesis researches. In this study, the malignant transformation of mouse embryonic stem cells (mESCs) pretreated with TCDD was investigated during their in vivo differentiation using teratoma formation model. Based on characterization of the pluripotency and differentiation capabilities of mESCs, evil changes in teratomas derived from TCDD-exposed mESCs were systematically studied. The results showed that TCDD significantly up-regulated CYP1A1 transcriptional levels in mESCs, elevated the incidence of malignant change in mESC-derived teratomas, and caused indefinite proliferation capabilities in sequential cultures of tumor tissues. The findings suggested that TCDD could exert carcinogenic effect on mESCs during their differentiation into teratoma in vivo, and more attention should be paid to the adverse health effects of this chemical during gestation or early developmental period.

Development of angiosarcoma in a mediastinal non-seminomatous germ cell tumor that exhibited growing teratoma syndrome during chemotherapy.

Herein, we report a case of an angiosarcoma in a mediastinal non-seminomatous germ cell tumor that exhibited growing teratoma syndrome during chemotherapy. A 26-year-old man presented with a giant anterior mediastinal mass, which was diagnosed as a non-seminomatous germ cell tumor. The patient was administered three cycles of chemotherapy (bleomycin, etoposide, and cisplatin), but the mass grew despite normalization of tumor markers. Massive bleeding during thoracic surgery resulted in incomplete resection, and the mass was clinically and pathologically diagnosed as growing teratoma syndrome (only mature teratoma). The residual mass continued to grow, and complete resection was subsequently achieved after a detailed analysis of its vascular anatomy using angiography. The final pathological findings revealed angiosarcoma, which indicated a rare somatic type of mediastinal non-seminomatous germ cell tumor.

Applying Radiomics to Predict Pathology of Postchemotherapy Retroperitoneal Nodal Masses in Germ Cell Tumors.

PURPOSE: After chemotherapy, approximately 50% of patients with metastatic testicular germ cell tumors (GCTs) who undergo retroperitoneal lymph node dissections (RPNLDs) for residual masses have fibrosis. Radiomics uses image processing techniques to extract quantitative textures/features from regions of interest (ROIs) to train a classifier that predicts outcomes. We hypothesized that radiomics would identify patients with a high likelihood of fibrosis who may avoid RPLND. PATIENTS AND METHODS: Patients with GCT who had an RPLND for nodal masses > 1 cm after first-line platinum chemotherapy were included. Preoperative contrast-enhanced axial computed tomography images of retroperitoneal ROIs were manually contoured. Radiomics features (n = 153) were used to train a radial basis function support vector machine classifier to discriminate between viable GCT/mature teratoma versus fibrosis. A nested 10-fold cross-validation protocol was used to determine classifier accuracy. Clinical variables/restricted size criteria were used to optimize the classifier. RESULTS: Seventy-seven patients with 102 ROIs were analyzed (GCT, 21; teratoma, 41; fibrosis, 40). The discriminative accuracy of radiomics to identify GCT/teratoma versus fibrosis was 72 ± 2.2% (area under the curve [AUC], 0.74 ± 0.028); sensitivity was 56.2 ± 15.0%, and specificity was 81.9 ± 9.0% ( P = .001). No major predictive differences were identified when data were restricted by varying maximal axial diameters (AUC range, 0.58 ± 0.05 to 0.74 ± 0.03). The prediction algorithm using clinical variables alone identified an AUC of 0.76. When these variables were added to the radiomics signature, the best performing classifier was identified when axial masses were limited to diameter < 2 cm (accuracy, 88.2 ± 4.4; AUC, 0.80 ± 0.05; P = .02). CONCLUSION: A predictive radiomics algorithm had a discriminative accuracy of 72% that improved to 88% when combined with clinical predictors. Additional independent validation is required to assess whether radiomics allows patients with a high predicted likelihood of fibrosis to avoid RPLND.

Exposure to ambient dichloromethane in pregnancy and infancy from industrial sources and childhood cancers in California.

BACKGROUND: The incidence of childhood cancers has been increasing and environmental exposure to air toxics has been suggested as a possible risk factor. This study aims to explore ambient exposure to dichloromethane (methylene chloride). METHODS: We frequency matched by birth year approximately 20 cancer-free controls identified from birth records to all childhood cancers ages 0-5 in the California Cancer Registry diagnosed from 1988 to 2012; i.e. 13,636 cases and a total of 270,673 controls. Information on industrial releases of dichloromethane within 3km of birth addresses was retrieved from mandatory industry reports to the EPA's Toxics Release Inventory (TRI). We derived exposure to dichloromethane within close vicinity of birth residences using several modeling techniques including unconditional logistic regression models with multiple buffer distances, inverse distance weighting, and quadratic decay models. RESULTS: We observed elevated risks for germ cell tumors [Odds Ratio (OR): 1.52, 95% Confidence Interval (CI) 1.11, 2.08], particularly teratomas (OR: 2.08, 95% CI 1.38-3.13), and possible increased risk for acute myeloid leukemias (AML) (OR: 1.64, 95% CI 1.15-2.32 in the quadratic decay model). Risk estimates were similar in magnitude whether releases occurred in pregnancy or the child's first year of life. CONCLUSION: Our findings suggest that exposure to industrial dichloromethane releases may be a risk factor for childhood germ cell tumors, teratomas, and possibly AML.

Leflunomide: a drug with a potential beyond rheumatology.

Leflunomide, an inhibitor of the dihydroorotase dehydrogenase and thereby pyrimidine synthesis, was introduced and licensed for the treatment of rheumatoid arthritis in 1998. In the following years, its antiviral properties were discovered and the drug was used in solid organ transplantation for polyomavirus type BK or cytomegalovirus infection. Owing to its long half-life and weak interaction with the cytochrome system, special considerations apply in the use of this drug. This article summarizes the clinical experience with leflunomide in rheumatology and in the evolving field of transplantation.

What's growing on? The growing teratoma syndrome.

BACKGROUND: The growing teratoma syndrome (GTS) consists of a mature teratoma paradoxically enlarging during or after chemotherapy for malignant nongerminomatous germ cell tumors. METHODS AND RESULTS: We report two cases of GTS occurring in association with NSGCT of the pineal gland. Although an unusual event, clinicians and radiologists should be aware of its natural history. CONCLUSIONS: When normalized tumor markers after chemotherapy are associated with imaging features of a growing mass, the hypothesis of GTS must be taken in consideration. When early diagnosed, GTS can be managed surgically with good results.

Early life inorganic lead exposure induces testicular teratoma and renal and urinary bladder preneoplasia in adult metallothionein-knockout mice but not in wild type mice.

Inorganic lead compounds are carcinogenic in animals and have carcinogenic potential in humans. In mice, lead (Pb) is a transplacental carcinogen in the kidney. Metallothionein (MT) is a metal-binding protein that can reduce the toxicity of various metals, including Pb, either by direct sequestration or as an antioxidant for metals that generate reactive oxygen species. Although MT appears to reduce Pb carcinogenicity in adult mice it is unknown how MT deficiency may affect Pb carcinogenicity from early life exposure. Thus, groups (n=10) of pregnant MT-I/II double knockout (MT-null) or 129/SVJ MT wild type (WT) mice were exposed to Pb acetate in the drinking water (0, 2000, 4000ppm Pb) from gestation day 8 through birth and during lactation. Maternal drinking water Pb exposure continued to wean at 4 weeks of age and the male offspring were then directly exposed to Pb until 8 weeks of age and observed until 2 years old. High dose (4000ppm) but not low dose (2000ppm) Pb reduced survival in the latter part of the study in both MT-null and WT mice. In MT-null mice, but not WT, early life Pb exposure caused a dose-related increase in testicular teratomas, to a maximum incidence of 28% compared to control (4%). Pb-induced renal cystic hyperplasia, considered preneoplastic, was a prominent occurrence in MT-null mice but nearly absent in WT mice. Pb dose-related increases in renal cystic hyperplasia occurred in adult MT-null with early life exposure with maximal incidence of 52%. Pb-treated MT-null mice also showed dose-related increases in urinary bladder hyperplasia with occasional papilloma that were absent in WT mice. Thus, MT deficiency made mice more sensitive to early life Pb exposure with regard to testes tumors, and renal and urinary bladder preneoplastic lesions.

Effects of limited doses of retinyl palmitate at the critical time of limb morphogenesis in mouse embryos.

With a view to examine the effects of defined doses of retinyl palmitate (Vit. A) on limb morphogenesis and their effects at the critical time in mouse embryos, pregnant Swiss Webster albino mice were administered retinyl palmitate (10000 or 15000 IU/kg, i.p.) on different days of pregnancy. Vitamin A in 15000 IU/kg, i.p. dose was most effective as produced malformations in the forelimbs by day 10 in 28.6% mice and in the hindlimbs by day 11 in 20.6% mice. Further, two injections in a day with the lower dose (10000 IU/kg, i.p.) had more teratogenic effects than single 15000 IU/kg, i.p. injection. Two injections of either dose on day 10 resulted in higher embryo absorption.

Intrauterine exposure to diethylstilbestrol: long-term effects in humans.

DES is the most carefully scrutinized EDC and its history provides valuable insights into the current evaluation of less well-studied EDCs. This review summarizes the health effects of prenatal exposure to diethylstilbestrol (DES) and emphasizes the role of DES as the first endocrine disrupting chemical (EDC). Vaginal clear cell adenocarcinoma (CCAC), the most severe consequence of prenatal exposure to DES, affected only 0.1% of exposed females, while the far more prevalent teratogenic and reproductive effects of DES were only discovered when DES daughter were screened for CCAC. Initial studies, conducted before most DES daughters had tried to conceive, examined vaginal cancer and vaginal, cervical and uterine abnormalities. Subsequently, several controlled studies demonstrated the increased risk of adverse reproductive outcomes in DES daughters. While most DES daughters can eventually experience a live birth, this is less likely in women with genital tract abnormalities, in whom there is a two-thirds chance that each pregnancy will be unsuccessful. In DES sons, who have been far less studied, results suggest male reproductive toxicity, but are less consistent. The importance of dose and gestational age at initial exposure are discussed, and the implications of DES findings for the evaluation of risks from current EDCs emphasized.

Growing teratoma syndrome after chemotherapy for germ cell tumors of the ovary.

BACKGROUND: The growing teratoma syndrome has been described with regard to gonadal and extragonadal germ cell neoplasms in males, but few cases have been reported in the female population. In this condition, masses that enlarge during or after chemotherapy are found to contain mature teratoma without malignant elements. CASES: Three patients had either persistent or growing masses despite chemotherapy for germ cell malignancies of the ovary. All cases fit the description of the growing teratoma syndrome. The patients were aged 20-22 years. All three patients had immature teratomas before chemotherapy. The stages of disease ranged from Ia to IIIc. All patients had normal tumor markers while their masses showed growth or persistence. All were free of disease 6-31 months after diagnosis. CONCLUSION: Growth or persistence of a tumor after chemotherapy for malignant teratoma does not necessarily imply progression of malignancy, especially if tumor markers are normal. However, these masses should be resected because they may cause obstruction, compression, or displacement of adjacent organs, or undergo sarcomatous degeneration.

Three cases of malignant neoplasm, pneumonitis, and pancytopenia during treatment with low-dose methotrexate.

A 77-year-old man with chronic obstructive pulmonary disease was treated with low-dose methotrexate (7.5-15 mg per week). After 15 months a diagnosis of urothelial carcinoma of the bladder was made; after a further 6 months pneumonitis and pancytopenia developed. The patient died due to massive pulmonary hemorrhage. A malignant teratoma was diagnosed in a 65-year-old asthmatic man 16 months after initiation of methotrexate therapy (15 mg per week). The patient died 4 months later due to fulminant progression of the neoplasm. A third malignant neoplasm (dermal squamous cell carcinoma) was seen in a 64-year-old woman with rheumatoid arthritis after 13 months treatment with 7.5 mg methotrexate per week. These three cases, while obviously not proving a causal relationship between long-term treatment with low-dose methotrexate and development of malignant neoplasm, do call for stringent treatment criteria, close surveillance, and prospective studies.

[Familial adult cystic kidneys and malignant teratomas after kidney transplantation with cyclosporin therapy]. / Familiäre adulte Zystennieren und maligne Teratome nach Nierentransplantation unter Ciclosporintherapie.

We report on two brothers with adult polycystic kidney disease, malignant teratomas and other genital malformations. Because of the unusual accumulation of malformations of embryologically related organs, we postulate a connection between malformations of the kidneys and the genital tract, on the one hand, and teratomas on the other. No genetic coherence is known so far. It is unlikely that immunosuppression with cyclosporin after transplantation had caused these tumours.