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Biological sex is a fundamental trait influencing development, reproduction, pathogenesis, and medical treatment outcomes. Modeling sex differences is challenging because of the masking effect of genetic variability and the hurdle of differentiating chromosomal versus hormonal effects. In this work we developed a cellular model to study sex differences in humans. Somatic cells from a mosaic Klinefelter syndrome patient were reprogrammed to generate isogenic induced pluripotent stem cell (iPSC) lines with different sex chromosome complements: 47,XXY/46,XX/46,XY/45,X0. Transcriptional analysis of the hiPSCs revealed novel and known genes and pathways that are sexually dimorphic in the pluripotent state and during early neural development. Female hiPSCs more closely resembled the naive pluripotent state than their male counterparts. Moreover, the system enabled differentiation between the contributions of X versus Y chromosome to these differences. Taken together, isogenic hiPSCs present a novel platform for studying sex differences in humans and bear potential to promote gender-specific medicine in the future., Competing Interests: Conflicts of interest B.E.R. is a member of the journal’s Editorial Board. B.E.R. is a founder of, holds shares in, and is the chief scientific officer of CellCure Neuroscience Ltd. The company did not fund the study presented in this paper and has no interest in its results. A patent application related to the data presented in this paper has been submitted., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

In the mammalian embryo, a formative pluripotent phase is proposed to exist at the early post-implantation period, during the transition from the pre-implantation naive-to the post-implantation primed-epiblast. By recapitulating a laminin component of the extracellular matrix niche during embryonic formative transition, and defined culture conditions, we generated cultures highly enriched for self-renewing human pluripotent stem cells (hPSCs), exhibiting properties of early post-implantation epiblast cells. These hPSCs display post-implantation-epiblast gene expression profiles. FGF and TGF-β signaling maintain their self-renewal for multiple passages. They have inactive canonical Wnt signaling, do not express primitive streak markers, and are competent to initiate differentiation toward germline and somatic fates. hPSCs exhibiting early post-implantation epiblast properties may shed light on human embryonic PSCs development and may serve for initiating somatic and germ cell specification., Competing Interests: Conflict of interests B.E.R. is a member of the journal’s Editorial Board. He is a founder, holds shares, and is the Chief Scientific Officer of CellCure Neuroscience Ltd. The company did not fund the study presented in this manuscript and has no interest in its results. A patent application related to the data presented in this manuscript has been submitted., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Pelvic organ prolapse (POP) is common among post-menopausal women and is associated with bladder, bowel, and sexual dysfunction. Surgical repair with the patients' native tissues is sub-optimal with high reoperation rates, potentially due to diminished age-related healing. We demonstrate that systemic transplantation of mesenchymal stem cells (MSCs) improves healing of full-thickness vaginal incision in the vaginal wall of old rats, as suggested by both histological and functional analysis. Transplanted MSCs homed and survived at the surgical vaginal site. Attenuation of the injury-induced inflammatory response, increased angiogenesis, and reduced matrix metalloproteinase 9 expression were observed at the surgical site of transplanted rats. Most importantly, the functional biomechanical properties of the healed vagina, at day 30 post-injury, were improved in MSC-transplanted, compared with sham-operated non-transplanted, old rats. These results may pave the way to further translational studies toward clinical transplantation of MSCs adjuvant to POP repair for the improvement of surgical outcome., Competing Interests: CONFLICTS OF INTEREST B.R. is a member of the journal’s editorial eoard. B.R. is a founder, holds shares, and is the chief scientific officer of CellCure Neuroscience, Ltd. The company did not fund the study presented in this manuscript and has no interest in its results., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To develop an efficient, clinical-grade, freezing protocol toward experimental clinical cryopreservation of testicular tissues in prepubertal boys suffering from cancer., Design: Experimental cryopreservation of testicular tissue., Setting: University Medical Center., Patients: Adult patients undergoing orchiectomy for various tumors and prepubertal boys scheduled for gonadotoxic treatment., Interventions: None., Main Outcome Measures: Histopathological analysis of tissue architecture, structural integrity, and cellular morphology was performed for control and frozen-thawed cryopreserved tissues.The number of seminiferous tubules per testicular section was calculated. The survival of spermatogonial stem cells (SSCs) and Sertoli cells of the control and frozen-thawed cryopreserved tissues was analyzed by immunofluorescence staining., Results: Uncontrolled Slow Freezing, Controlled slow freezing, and vitrification similarly preserved the integrity of the adult testicular tissues and the survival of SSCs and Sertoli cells. Controlled slow freezing of prepubertal testicular tissues effectively preserved their architecture, the number of tubules, SSCs, and Sertoli cells. In addition, we observed SSC loss after chemotherapy in prepubertal boys, reemphasizing the importance of fertility preservation before gonadotoxic treatment ., Conclusions: Future fertility restoration for male survivors of pediatric cancers depends on the development of an optimal prepubertal testicular tissue cryopreservation method. Our findings demonstrate the effectiveness of controlled slow freezing for cryopreservation of human prepubertal testicular tissues and may contribute to more effective banking of these tissues and potential fertility restoration., Clinical Trial Registration Number: NIH research clinical trials number: NCT02529826., (© 2021 The Authors.)

Background: Communication in the intensive care setting (ICS) is critical for both the patient and the medical staff to provide efficient care and thus alleviate possible patient adverse effects. Persons with complex communication needs are particularly vulnerable in ICSs and therefore require additional communication support., Aim: This study focused on the perspectives of nurses about communication with patients with communication needs in ICSs using paper-based communication boards, namely the translated Vidatak EZ Board, before and after a training session., Setting: A 1650-bed public hospital with a 26-bed ICS in a semi-urban, low socio-economic area in South Africa served as the research setting., Methods: A quasi-experimental pre-test post-test group design with withdrawal and a control group was used. Data were gathered using a custom-designed questionnaire completed by ICS nurse participants recruited from a public hospital., Results: Responses of some nurses did not change in post-test 1, but their responses did change in post-test 2. Some of the nurses' perspectives changed, as expected from the pre-test to post-test 1. Nurses recommended specific adaptations to the communication board., Conclusions: Most nurses agreed that communication is crucial in ICSs and that a communication board can be implemented; however, limited success was observed implementing the board following a short training. The inter-professional collaboration between nurses and speech-language therapists to provide optimal health care to patients in ICS is emphasised., Competing Interests: The authors declare that they have no financial or personal relationships that may have inappropriately influenced them in writing this article., (© 2019. The Authors.)

The beneficial effect of mesenchymal stem cells (MSCs) on wound healing is mostly attributed to a trophic effect that promotes angiogenesis. Whether MSCs can contribute to the formation of new blood vessels by direct differentiation is still controversial. Pelvic floor dysfunction (PFD) is a group of disorders that negatively affect the quality of women's lives. Traditional vaginal surgical repair provides disappointing anatomical outcome. Stem cell transplantation may be used to supplement surgery and improve its outcome. Here we aimed to examine the engraftment, survival, differentiation and angiogenic effect of transplanted MSCs in a vaginal injury rat model. MSCs were obtained from the bone marrow of Sprague Drawley (SD) rats, expanded and characterized in vitro. The MSCs expressed CD90 and CD29, did not express CD45, CD34, CD11b and CD31 and could differentiate into osteogenic, chondrogenic and adipogenic lineages. Cells were labeled with either PKH-26 or GFP and transplanted systemically or locally to female SD rats, just after a standardized vaginal incision was made. Engraftment after local transplantation was less efficient at all-time points compared to systemic administration. In the systemically transplanted animal group, MSCs migrated to the injury site and were present in the healed vagina for at least 30 days. Both systemic and local MSCs transplantation promoted host angiogenesis. Systemically transplanted MSCs created new vascular-like structures by direct differentiation into endothelium. These findings pave the way to further studies of the potential role of MSCs transplantation in improving surgical outcome in women with PFD., Competing Interests: We declare that no competing interests exist. Benjamin Reubinoff is a founder, holds shares and is the Chief Scientific Officer of CellCure Neuroscience Ltd. The focus of the company is the development of human embryonic stem cells for transplantation therapy in neurological and retinal degeneration disorders. The company did not fund the study presented in this manuscript and has no interest in its results. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Fragile X syndrome is the most frequent cause of inherited intellectual disability. The primary molecular defect in this disease is the expansion of a CGG repeat in the 5' region of the fragile X mental retardation1 (FMR1) gene, leading to de novo methylation of the promoter and inactivation of this otherwise normal gene, but little is known about how these epigenetic changes occur during development. In order to gain insight into the nature of this process, we have used cell fusion technology to recapitulate the events that occur during early embryogenesis. These experiments suggest that the naturally occurring Fragile XFMR1 5' region undergoes inactivation post implantation in a Dicer/Ago-dependent targeted process which involves local SUV39H-mediated tri-methylation of histone H3K9. It thus appears that Fragile X syndrome may come about through inadvertent siRNA-mediated heterochromatinization.

Congenital human cytomegalovirus (HCMV) infection is associated with neurodevelopmental disabilities. To dissect the earliest events of infection in the developing human brain, we studied HCMV infection during controlled differentiation of human embryonic stem cells (hESC) into neural precursors. We traced a transition from viral restriction in hESC, mediated by a block in viral binding, toward HCMV susceptibility in early hESC-derived neural precursors. We further revealed the role of platelet-derived growth factor receptor alpha (PDGFRα) as a determinant of the developmentally acquired HCMV susceptibility., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

The function of imprinted H19 long non-coding RNA is still controversial. It is highly expressed in early embryogenesis and decreases after birth and re-expressed in cancer. To study the role of H19 in oncogenesis and pluripotency, we down-regulated H19 expression in vitro and in vivo in pluripotent human embryonic carcinoma (hEC) and embryonic stem (hES) cells. H19 knockdown resulted in a decrease in the expression of the pluripotency markers Oct4, Nanog, TRA-1-60 and TRA-1-81, and in the up-regulation of SSEA1; it further attenuated cell proliferation, decreased cell-matrix attachment, and up-regulated E-Cadherin expression. SCID-Beige mice transplanted with H19 down-regulated hEC cells exhibited slower kinetics of tumor formation, resulting in an increased animal survival. Tumors derived from H19 down-regulated cells showed a decrease in the expression of pluripotency markers and up-regulation of SSEA-1 and E-cadherin. Our results suggest that H19 oncogenicity in hEC cells is mediated through the regulation of the pluripotency state.

Teratoma tumor formation is an essential criterion in determining the pluripotency of human pluripotent stem cells. However, currently there is no consistent protocol for assessment of teratoma forming ability. Here we present detailed characterization of a teratoma assay that is based on subcutaneous co-transplantation of defined numbers of undifferentiated human embryonic stem cells (hESCs) with mitotically inactivated feeder cells and Matrigel into immunodeficient mice. The assay was highly reproducible and 100% efficient when 100,000 hESCs were transplanted. It was sensitive, promoting teratoma formation after transplantation of 100 hESCs, though larger numbers of animals and longer follow-up were required. The assay could detect residual teratoma forming cells within differentiated hESC populations however its sensitivity was decreased in the presence of differentiated cells. Our data lay the foundation, for standardization of a teratoma assay for pluripotency analysis. The assay can also be used for bio-safety analysis of pluripotent stem cell-derived differentiated progeny.

The International Stem Cell Initiative analyzed 125 human embryonic stem (ES) cell lines and 11 induced pluripotent stem (iPS) cell lines, from 38 laboratories worldwide, for genetic changes occurring during culture. Most lines were analyzed at an early and late passage. Single-nucleotide polymorphism (SNP) analysis revealed that they included representatives of most major ethnic groups. Most lines remained karyotypically normal, but there was a progressive tendency to acquire changes on prolonged culture, commonly affecting chromosomes 1, 12, 17 and 20. DNA methylation patterns changed haphazardly with no link to time in culture. Structural variants, determined from the SNP arrays, also appeared sporadically. No common variants related to culture were observed on chromosomes 1, 12 and 17, but a minimal amplicon in chromosome 20q11.21, including three genes expressed in human ES cells, ID1, BCL2L1 and HM13, occurred in >20% of the lines. Of these genes, BCL2L1 is a strong candidate for driving culture adaptation of ES cells.

Purpose: One attempt to improve long-term survival in patients with advanced ovarian cancer was thought to be the addition of more non-cross-resistant drugs to platinum-paclitaxel combination regimens. Gemcitabine was among the candidates for a third drug., Patients and Methods: We performed a prospective, randomized, phase III, intergroup trial to compare carboplatin plus paclitaxel (TC; area under the curve [AUC] 5 and 175 mg/m(2), respectively) with the same combination and additional gemcitabine 800 mg/m(2) on days 1 and 8 (TCG) in previously untreated patients with advanced epithelial ovarian cancer. TC was administered intravenously (IV) on day 1 every 21 days for a planned minimum of six courses. Gemcitabine was administered by IV on days 1 and 8 of each cycle in the TCG arm., Results: Between 2002 and 2004, 1,742 patients were randomly assigned; 882 and 860 patients received TC and TCG, respectively. Grades 3 to 4 hematologic toxicity and fatigue occurred more frequently in the TCG arm. Accordingly, quality-of-life analysis during chemotherapy showed a disadvantage in the TCG arm. Although objective response was slightly higher in the TCG arm, this did not translate into improved progression-free survival (PFS) or overall survival (OS). Median PFS was 17.8 months for the TCG arm and 19.3 months for the TC arm (hazard ratio [HR], 1.18; 95% CI, 1.06 to 1.32; P = .0044). Median OS was 49.5 for the TCG arm and 51.5 months for the TC arm (HR, 1.05; 95% CI, 0.91 to 1.20; P = .5106)., Conclusion: The addition of gemcitabine to carboplatin plus paclitaxel increased treatment burden, reduced PFS time, and did not improve OS in patients with advanced epithelial ovarian cancer. Therefore, we recommend no additional clinical use of TCG in this population.

Dysfunction and loss of retinal pigment epithelium (RPE) leads to degeneration of photoreceptors in age-related macular degeneration and subtypes of retinitis pigmentosa. Human embryonic stem cells (hESCs) may serve as an unlimited source of RPE cells for transplantation in these blinding conditions. Here we show the directed differentiation of hESCs toward an RPE fate under defined culture conditions. We demonstrate that nicotinamide promotes the differentiation of hESCs to neural and subsequently to RPE fate. In the presence of nicotinamide, factors from the TGF-beta superfamily, which presumably pattern RPE development during embryogenesis, further direct RPE differentiation. The hESC-derived pigmented cells exhibit the morphology, marker expression, and function of authentic RPE and rescue retinal structure and function after transplantation to an animal model of retinal degeneration caused by RPE dysfunction. These results are an important step toward the future use of hESCs to replenish RPE in blinding diseases.

Objective: Effective therapies with a low rate of side effects are warranted in the 2nd-line setting in ovarian cancer. Both topotecan and the alkylating agent treosulfan have demonstrated efficacy in this patient group and are broadly used in Germany. Therefore, we started a prospectively randomized phase III trial comparing these two drugs in early recurrent ovarian cancer., Methods: Patients having relapsed after platinum-taxane therapy were randomized to receive either topotecan or treosulfan. Stratification depended on platinum sensitivity (stratum 1: up to 6 months after primary chemotherapy, stratum 2: 6 to 12 months)., Results: A total of 274 patients were treated either with topotecan (136 patients) or treosulfan (138). Hematologic toxicity was significantly more frequent with topotecan but without severe clinical consequences. Non hematologic toxicity was similar in both study arms. Overall survival was significantly longer with topotecan (p=0.0023), with a median of 55.0 weeks versus 41.0 weeks as well as progression-free survival (p=0.0020) with a median of 23.1 weeks versus 12.7 weeks. Similar results were found for stratum 2 subgroup. Overall response rate was 27.5% for topotecan and 16.0% for treosulfan (p=0.0307). In stratum 1 progression-free survival was 18.1 weeks for topotecan and 9.4 weeks for treosulfan (p=0.0476), but there was no difference in overall survival in this prognostic poor subgroup., Conclusions: This randomized phase III trial could detect superiority of topotecan versus treosulfan in patients with recurrent disease after platinum-paclitaxel combination therapy. Our experience indicates that optimization of systemic treatment could improve outcome even in this poor prognostic subgroup of patients with relapsed ovarian cancer.

A femtosecond laser beam gene transduction (SG-LBGT) system is described as a novel and efficient method of intradermal (i.d.) nonviral gene delivery in mice by permeabilizing cells utilizing femtosecond laser pulses. Using this approach, significant gene expression and efficient dermal transduction lasting for >7 months were obtained. The ability of this new DNA gene transfer method to enhance genetic vaccination was tested in BALB/C mice. A single i.d. injection of a plasmid (10 microg) containing the hepatitis B virus (HBV) surface antigen (HBsAg), followed by pulses of laser, induced high titers of HBsAg-specific antibodies lasting for >210 days and increased levels of IgG1, IgG2a, IFNgamma, and IL-4, indicating the activation of both Th1 and Th2 cells. Moreover, mice vaccinated using the SG-LBGT followed by challenge with pHBV showed increased protection against viral challenge, as detected by decreased levels of HBV DNA, suggesting an efficient Th1 effect against HBV-infected replicating cells. Tumor growth retardation was induced in vaccinated mice challenged with an HBsAg-expressing syngeneic tumor. In most of the parameters tested, administration of plasmid followed by laser application was significantly more effective and prolonged than that of plasmid alone. Tissue damage was not detected and integration of the plasmid into the host genomic DNA probably did not occur. We suggest that the LBGT method is an efficient and safe technology for in vivo gene expression and vaccination and emphasizes its potential therapeutic applications for i.d. nonviral gene delivery.

Genetic modifications of human embryonic stem cells (hESCs) that will efficiently promote stable homogenous gene silencing, and will also allow monitoring of the silencing level, may be invaluable for the study of function of genes in early human embryogenesis, differentiation, and maintenance of pluripotency of hESCs. RNA-mediated interference (RNAi) emerges as a highly efficient tool for specific knockdown of gene expression. Lentiviruses are efficient vectors for the delivery and stable expression of transgenes in hESCs. We sought to develop a lentiviral-RNAi-based system that will efficiently induce homogenous gene silencing and will allow the monitoring of its relative level in hESCs. Dual-promoter lentiviral vectors coexpressing an RNAi cassette and a reporter gene were initially used for efficient and stable induction of heterogeneous levels of gene silencing in polyclonal hESCs. This step was further combined with the isolation of transduced clones with different homogenous levels of gene silencing. The level of silencing in each of the clones correlated and could be monitored by the level of expression of the vector's reporter transgene. Thus, our system allows easy identification of clones with relatively different homogenous levels of gene silencing. Our approach would be valuable for the study of function of genes, in particular those whose role in hESCs biology depends on their level of expression.

Background: Tamoxifen and gefitinib (IRESSA) combination therapy was studied in patients with ovarian cancer refractory or resistant to platinum- and taxane-based therapy., Patients and Methods: In this phase II study, 56 patients with epithelial ovarian carcinoma or cancer of the fallopian tube or peritoneum received oral tamoxifen 40 mg/day and gefitinib 500 mg/day until progression or unacceptable toxicity., Results: Seventeen patients (mean age: 59.6 years) had previously received first-line platinum/taxane treatment only, while 39 had received 2-8 (median 2) prior chemotherapy regimens. Gefitinib dose reduction to 250 mg/day was performed in 10 patients (14.9%), predominantly due to diarrhea (6 patients [10.7%]). Trial medication was discontinued in 6 patients (10.7%) due to adverse events (AEs). The most frequent drug-related AEs were diarrhea and acne-like skin rash. There were no tumor responses, but 16 patients had stable disease. Median time-to-progression was 58 days (95% CI, 55-71 days) and median survival was 253 days (95% CI, 137-355 days)., Conclusion: Gefitinib plus tamoxifen did not appear to be efficacious in the treatment of patients with refractory/resistant ovarian cancer. The addition of tamoxifen did not worsen the known side effects of gefitinib, or induce additional side effects.

Ataxia-telangiectasia (A-T) is a multi-system genomic instability syndrome that is caused by loss or inactivation of the ATM protein kinase. ATM is largely nuclear in proliferating cells, and activates an extensive network of pathways in response to double strand breaks (DSBs) in the DNA by phosphorylating key proteins in these pathways. The prominent symptom of A-T is neuronal degeneration, making the elucidation of ATM's functions in neurons essential to understanding the disease. It has been suggested that ATM is cytoplasmic in neurons and functions in processes that are not associated with the DNA damage response. Recently we showed that in human neuron-like cells obtained by in vitro differentiation of neuroblastomas, ATM was largely nuclear and mediated the DSB response as in proliferating cells. We have now extended these studies to two additional model systems: neurons derived from human embryonic stem cells, and cortical neurons derived from neural stem cells. The results substantiate the notion that ATM is nuclear in human neurons and mediates the DSB response, the same as it does in proliferating cells. We present here unique and powerful model systems to further study the ATM-mediated network in neurons.

Background: The role of cytoreductive surgery in relapsed ovarian cancer is not clearly defined. Therefore, patient selection remains arbitrary and depends on the center's preference rather than on established selection criteria. The Descriptive Evaluation of preoperative Selection KriTeria for OPerability in recurrent OVARian cancer (DESKTOP OVAR) trial was undertaken to form a hypothesis for a panel of criteria for selecting patients who might benefit from surgery in relapsed ovarian cancer., Methods: The DESKTOP trial was an exploratory study based on data from a retrospective analysis of hospital records. Twenty-five member institutions of the Arbeitsgemeinschaft Gynaekologische Onkologie Ovarian Committee (AGO OC) and AGO-OVAR boards collected data on their patients with cytoreductive surgery for relapsed invasive epithelial ovarian cancer performed in 2000-2003., Results: Two hundred and sixty-seven patients were included. Complete resection was associated with significantly longer survival compared with surgery leaving any postoperative residuals [median 45.2 vs. 19.7 months; hazard ratio (HR) 3.71; 95% confidence interval (CI) 2.27-6.05; P < .0001]. Variables associated with complete resection were performance status (PS) [Eastern Cooperative Oncology Group (ECOG) 0 vs. > 0; P < .001], International Federation of Gynecology and Obstetrics (FIGO) stage at initial diagnosis (FIGO I/II vs. III/IV, P = .036), residual tumor after primary surgery (none vs. present, P <.001), and absence of ascites > 500 ml (P < .001). A combination of PS, early FIGO stage initially or no residual tumor after first surgery, and absence of ascites could predict complete resection in 79% of patients., Conclusions: Only complete resection was associated with prolonged survival in recurrent ovarian cancer. The identified criteria panel will be verified in a prospective trial (AGO-DESKTOP II) evaluating whether it will render a useful tool for selecting the right patients for cytoreductive surgery in recurrent ovarian cancer.

Human embryonic stem cells (hESCs) are pluripotent cells derived from the inner cell mass of preimplantation embryos. These cells can be cultured for long periods as undifferentiated cells and still retain their potential to give rise to cell types representing all three germinal layers. Given their unique properties, hESCs are expected to serve as an invaluable tool for basic and applied research. However, to exploit their remarkable potentials, the development of effective strategies for genetic modification of hESCs is required. Lentiviral-based vectors offer an attractive system for efficient gene delivery into hESCs. These vectors are derived from lentiviruses, a group of complex retroviruses that cause slow chronic immunodeficiency diseases in humans and animals. Gene delivery into hESCs by vectors derived from lentiviruses has the following advantages: (1) lentiviral vectors efficiently transduce hESCs; (2) they integrate into the host-cell genome, thus promoting stable transgene expression; (3) transgene expression is not significantly silenced in hESCs; and (4) transduced hESCs retain their self-renewal and pluripotent potential. In recent years, we and others have developed protocols for efficient transduction of hESCs by advanced modified replication-defective lentiviral-based vectors. Transduction of hESCs by these vectors resulted in high and stable transgene expression that was maintained over long periods of undifferentiated cultivation and after differentiation. This chapter focuses on methods for the use of lentiviral-based vectors for gene delivery into hESCs.

The role of cytoreductive surgery (CS) in recurrent ovarian cancer (ROC) has not been clearly defined. We performed a retrospective study evaluating criteria for CS in ROC. Twenty-five institutions documented their patients with CS for invasive epithelial ROC performed 2000-2003. Two hundred sixty-seven patients were included. Complete tumor removal was achieved in 133 patients (50%). Complete resection was associated with prolonged survival compared to surgeries with residual tumor. Median survival of patients without residual tumor was 45.3 months and of patients with residual tumor, irrespective of its size, 19.0 months (HR 4.33; 95% CI 2.53-7.43; P < 0.0001). In a multivariate analysis, the following factors showed a significant influence on the probability to achieve a postoperative residual tumor of 0 mm: absence of ascites (<500 vs > or =500 mL: HR 4.63; 95% CI: 1.81-11.76; P= 0.0001), good performance status Eastern Cooperative Oncology Group (ECOG) 0 vs >0: HR: 2.41; 95% CI: 1.41-4.08; P= 0.001, and low FIGO stage at primary diagnosis (FIGO I/II vs III/IV: HR 1.87; 95% CI: 1.04-3.37; P= 0.036). Significant factors for survival after surgery for recurrence in a multivariate analysis were achievement of complete resection (residual tumor at surgery for recurrence 0 vs >0 mm: HR 2.86; 95% CI: 1.66-4.93; P < 0.001), absence of ascites (<500 vs > or =500 mL: HR 2.09; 95% CI: 1.18-3.71; P= 0.012), and application of a platinum-containing chemotherapy (platinum-containing chemotherapy vs others: HR 1.83; 95% CI: 1.16-2.88; P= 0.009). Only patients with complete resection seem to benefit from CS. This new panel of selection criteria will be evaluated in a prospective study.

Human embryonic stem (hES) cells are pluripotent cells derived from the inner cell mass of the early preimplantation embryo. An efficient strategy for stable genetic modification of hES cells may be highly valuable for manipulating the cells in vitro and may promote the study of hES cell biology, human embryogenesis, and the development of cell-based therapies. Here, we demonstrate that vectors derived from self-inactivating (SIN) human immunodeficiency virus type 1 (HIV-1) are efficient tools for stable genetic modification of hES cells. Transduction of hES cells by a modified vector derived from SIN HIV-1 and containing the woodchuck hepatitis regulatory element (WPRE) and the central polypurine tract (cPPT) sequence facilitated stable transgene expression during prolonged (38 weeks) undifferentiated proliferation in vitro. Southern blot analysis revealed that the viral vector had integrated into the host cells' DNA. Transgene expression was maintained throughout differentiation into progeny of all three germ layers both in vitro and in vivo in teratomas. Thus, the transduced hES cells retained the capability for self-renewal and their pluripotent potential. Genetic modification of hES cells by lentiviral vectors provides a powerful tool for basic and applied research in the area of human ES cells.

Purpose: Urokinase-type plasminogen activator (uPA) and its inhibitor, plasminogen activator inhibitor (PAI)-1, have been shown to be related to poor prognosis in a variety of malignant solid tumors. Studies on the prognostic relevance of uPA and PAI-1 in ovarian cancer, however, have been inconclusive. The current study tests the hypothesis that elevated expression of uPA and PAI-1 is associated with prognosis and disease progression., Experimental Design: uPA and PAI-1 were prospectively measured by quantitative ELISA in tumor samples from 103 ovarian cancer patients (82 primary invasive epithelial carcinomas, 9 low malignant potential tumors, and 12 recurrent ovarian carcinomas)., Results: uPA but not PAI-1 levels were consistently associated with malignant progression, with levels increased from low malignant potential tumors to primary tumors (uPA, P = 0.04; PAI-1, P = 0.019), from early to advanced disease stages (uPA, P = 0.014; PAI-1, P = 0.23), and from primary to intra-abdominal metastatic tumors (uPA, P = 0.001; PAI-1, P = 0.16). High uPA and PAI-1 levels were associated with residual tumor volumes of >1 cm (P = 0.001 and P = 0.016, respectively). Among invasive International Federation of Gynecologists and Obstetrician stages I-IV tumors, elevated levels of uPA (>5.5 ng/mg) and PAI-I (>18.8 ng/ml) were associated with a shortened progression-free survival (uPA, P = 0.003; PAI-1, P = 0.039) and overall survival (uPA, P = 0.0002; PAI-1, P = 0.007). In multivariate analysis, uPA retained prognostic independence for progression-free survival (P = 0.037) and overall survival (P = 0.006)., Conclusions: These data suggest that the uPA/PAI-1 axis may play an important role in the intra-abdominal spread and reimplantation of ovarian cancer cells. The prognostic relevance of uPA and PAI-1 supports their possible role in the malignant progression of ovarian cancer.

The E. coli RelA protein is a ribosome-dependent (p)ppGpp synthetase that is activated in response to amino acid starvation. RelA can be dissected both functionally and physically into two domains: The N-terminal domain (NTD) (amino acids [aa] 1 to 455) contains the catalytic domain of RelA, and the C-terminal domain (CTD) (aa 455 to 744) is involved in regulating RelA activity. We used mutational analysis to localize sites important for RelA activity and control in these two domains. We inserted two separate mutations into the NTD, which resulted in mutated RelA proteins that were impaired in their ability to synthesize (p)ppGpp. When we caused the CTD in relA(+) cells to be overexpressed, (p)ppGpp accumulation during amino acid starvation was negatively affected. Mutational analysis showed that Cys-612, Asp-637, and Cys-638, found in a conserved amino acid sequence (aa 612 to 638), are essential for this negative effect of the CTD. When mutations corresponding to these residues were inserted into the full-length relA gene, the mutated RelA proteins were impaired in their regulation. In attempting to clarify the mechanism through which the CTD regulates RelA activity, we found no evidence for competition for ribosomal binding between the normal RelA and the overexpressed CTD. Results from CyaA complementation experiments of the bacterial two-hybrid system fusion plasmids (G. Karimova, J. Pidoux, A. Ullmann, and D. Ladant, Proc. Natl. Acad. Sci. USA 95:5752-5756, 1998) indicated that the CTD (aa 564 to 744) is involved in RelA-RelA interactions. Our findings support a model in which RelA activation is regulated by its oligomerization state.

Loss of function of the tumor suppressor gene p53, increased expression of glutathione-S-transferase pi (GST7pi) and the major vault protein are involved in drug resistance of ovarian carcinomas. However, a study comparing these factors has not yet been performed. Therefore, paraffin-embedded material of 213 ovarian tumors with well-documented follow-up was used for immunohistochemical analysis of p53 protein, GSTpi, and major vault protein (antibodies LRP-56, LMR-5). Forty-six percent of the cases showed nuclear p53 accumulation. Strong immunoreactivity for GSTpi, LRP-56, and LMR-5 was seen in 50%, 36%, and 47%, respectively. p53 positivity was most often found in serous carcinomas (p < 0.05). Strong GSTpi expression was the only factor that correlated with clinical resistance to chemotherapy (p = 0.04). In the whole group, as well as in FIGO III cases stratified for residual disease < or = and >2 cm, p53 and GSTpi correlated with an adverse outcome (p = 0.01 for p53 and p = 0.04 for GSTpi). Strong LRP-56 or LMR-5 staining was associated with a tendency towards poorer prognosis, without reaching statistical significance. In multivariate analysis for FIGO III, only residual disease and p53 proved to be independent prognostic factors. Our observations confirm the prognostic significance of p53 accumulation in ovarian carcinomas. Only GSTpi immunoreactivity was significantly correlated with drug resistance.

Prognostic outcome of patients with bulky disease after primary surgery in ovarian cancer remains extremely poor. One possible approach to achieve prolonged survival is secondary debulking surgery, but only in those patients without residual tumor after the second surgery. In 79 patients with secondary debulking surgery preoperative CA125 values were determined. In 52% of the patients with CA125 values below 35 U/ml a tumor free situation could be achieved at secondary debulking. In contrast, the percentage of patients macroscopically free of disease with levels above 35 U/ml was only 22%. Furthermore, there was a significant difference in survival time depending on CA125 values at the time of secondary debulking. Patients with levels below 35 U/ml survived 49 months, women with values above 35 U/ml survived only 30 months respectively. In conclusion, CA125 is an important prognostic tool for predicting a tumor free situation at secondary debulking surgery. In patients with values above 35 U/ml secondary debulking should be indicated restrictively, even if other preoperative diagnostic tools would predict a tumor free situation after secondary cytoreductive surgery.

The histidine analog 3-amino-1,2,4-triazole (AT) was used for the selection of spontaneous AT-resistant revertants of a relA mutant of Bacillus subtilis. One of these revertants, L3, showed a unique phenotype; it did not respond to amino acid starvation, like the relA mutant, but it did respond to glucose starvation by the accumulation of (p)ppGpp, unlike its parent. Genetic analysis revealed that this suppressor mutant (relA(S)) allele mapped to the relA locus at 239 degrees on the B. subtilis chromosome.