Effect of 3α-dihydroprogesterone and 5α-dihydroprogesterone on DCIS cells and possible impact for postmenopausal women

OBJECTIVE

Progesterone metabolites 5α-dihydroprogesterone (5αP) and 3α-dihydroprogesterone (3αP) have opposite effects on proliferation, apoptosis and metastasis in the breast. Evidence regarding their influence on ductal carcinoma in situ (DCIS) lesions is lacking.

METHODS

MCF10DCIS.com cells were cultured in a 3D culture system and treated with 5αP or 3αP. After 5 and 12 days of treatment, polymerase chain reaction (PCR) of proliferation, invasion/metastasis, anti-apoptotic or other markers was performed. Cells treated with the tumor-promoting 5αP were observed under the light and confocal microscopes to reveal possible morphological changes that could indicate a transition from an in situ to an invasive phenotype. As a control, the morphology of the MDA-MB-231 invasive cell line was examined. The invasive potential after exposure to 5αP was also assessed using a detachment assay.

RESULTS

The PCR analysis of the chosen markers showed no statistically significant difference between naive cells and cells treated with 5αP or 3αP. DCIS spheroids retained their in situ morphology after treatment with 5αP. The detachment assay showed no increased potential for invasion after exposure to 5αP. Progesterone metabolites 5αP and 3αP do not facilitate or prohibit tumor promotion/invasion in MCF10DCIS.com cells, respectively.

CONCLUSION

As oral micronized progesterone has been proved effective for hot flushes in postmenopausal women, first in vitro data propose that progesterone-only therapy could possibly be considered for women after DCIS suffering from hot flushes.

Modulation of Host-Parasite Interactions with Small Molecules Targeting Schistosoma mansoni microRNAs

Parasites use different strategies of communication with their hosts. One communication channel that has been studied in recent years is the use of vesicle microRNAs to influence the host immune system by trematodes. sma-microRNA-10, secreted from Schistosoma mansoni, has been shown to influence the fate of host T-cells through manipulation of the NF-κB pathway. We have identified low molecular weight tool compounds that can interfere with this microRNA-mediated manipulation of the host immune system. We used a fragment-based screening approach by means of nuclear magnetic resonance (NMR) to identify binders to the precursor of the parasite sma-microRNA-10 present in their extracellular vesicles. The small fragments identified were used to select larger molecules. These molecules were shown to counteract the inhibition of NF-κB activity by sma-microRNA-10 in cell-based assays.

The ellagic acid metabolites urolithin A and B differentially affect growth, adhesion, motility, and invasion of endometriotic cells in vitro

STUDY QUESTION

What are the effects of plant-derived antioxidant compounds urolithin A (UA) and B (UB) on the growth and pathogenetic properties of an in vitro endometriosis model?

SUMMARY ANSWER

Both urolithins showed inhibitory effects on cell behavior related to the development of endometriosis by differentially affecting growth, adhesion, motility, and invasion of endometriotic cells in vitro.

WHAT IS KNOWN ALREADY

Endometriosis is one of the most common benign gynecological diseases in women of reproductive age and is defined by the presence of endometrial tissue outside the uterine cavity. As current pharmacological therapies are associated with side effects interfering with fertility, we aimed at finding alternative therapeutics using natural compounds that can be administered for prolonged periods with a favorable side effects profile.

STUDY DESIGN, SIZE, DURATION

In vitro cultures of primary endometriotic stromal cells from 6 patients subjected to laparoscopy for benign pathologies with histologically confirmed endometriosis; and immortalized endometrial stromal (St-T1b) and endometriotic epithelial cells (12Z) were utilized to assess the effects of UA and UB on endometriotic cell properties. Results were validated in three-dimensional (3D) in vitro co-culture spheroids of 12Z and primary endometriotic stroma cells of one patient, and organoids from 3 independent donors with endometriosis.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The effects on cell growth were measured by non-radioactive colorimetric assay to measure cellular metabolic activity as an indicator of cell viability (MTT assay) and flow cytometric cell cycle assay on primary cultures, St-T1b, and 12Z. Apoptosis analyses, the impact on in vitro adhesion, migration, and invasion were evaluated in the cell lines. Moreover, Real-Time Quantitative Reverse Transcription polymerase chain reaction (RT-qPCR) assays were performed on primary cultures, St- T1b and 12Z to evaluate a plausible mechanistic contribution by factors related to proteolysis (matrix metalloproteinase 2, 3 and 9 -MMP2, MMP3, MMP9-, and tissue inhibitor of metalloproteinases -TIMP-1-), cytoskeletal regulators (Ras-related C3 botulinum toxin substrate 1 -RAC1-, Rho-associated coiled-coil containing protein kinase 2 -ROCK2-), and cell adhesion molecules (Syndecan 1 -SDC1-, Integrin alpha V-ITGAV-). Finally, the urolithins effects were evaluated on spheroids and organoids by formation, viability, and drug screen assays.

MAIN RESULTS AND THE ROLE OF CHANCE

40 µM UA and 20 µM UB produced a significant decrease in cell proliferation in the primary endometriotic cell cultures (P < 0.001 and P < 0.01, respectively) and in the St-T1b cell line (P < 0.001 and P < 0.05, respectively). In St-T1b, UA exhibited a mean half-maximum inhibitory concentration (IC50) of 39.88 µM, while UB exhibited a mean IC50 of 79.92 µM. Both 40 µM UA and 20 µM UB produced an increase in cells in the S phase of the cell cycle (P < 0.01 and P < 0.05, respectively). The same concentration of UA also increased the percentage of apoptotic ST-t1b cells (P < 0.05), while both urolithins decreased cell migration after 24 h (P < 0.001 both). Only the addition of 5 µM UB decreased the number of St-T1b adherent cells. TIMP-1 expression was upregulated in response to treating the cells with 40 µM UA (P < 0.05). Regarding the 12Z endometriotic cell line, only 40 µM UA decreased proliferation (P < 0.01); while both 40 µM UA and 20 µM UB produced an increase in cells in the G2/M phase (P < 0.05 and P < 0.01, respectively). In this cell line, UA exhibited a mean IC50 of 40.46 µM, while UB exhibited a mean IC50 of 54.79 µM. UB decreased cell migration (P < 0.05), and decreased the number of adherent cells (P < 0.05). Both 40 µM UA and 20 µM UB significantly decreased the cellular invasion of these cells; and several genes were altered when treating the cells with 40 µM UA and 10 µM UB. The expression of MMP2 was downregulated by UA (P < 0.001), and expression of MMP3 (UA P < 0.001 and UB P < 0.05) and MMP9 (P < 0.05, both) were downregulated by both urolithins. Moreover, UA significantly downregulated ROCK2 (P < 0.05), whereas UB treatment was associated with RAC1 downregulation (P < 0.05). Finally, the matrix adhesion receptors and signaling (co)receptors SDC1 and ITGAV were downregulated upon treatment with either UA or UB (P < 0.01 and P < 0.05, respectively in both cases). Regarding the effects of urolithins on 3D models, we have seen that they significantly decrease the viability of endometriosis spheroids (80 µM UA and UB: P < 0.05 both) as well as affecting their area (40 µM UA: P < 0.05, and 80 µM UA: P < 0.01) and integrity (40 µM UA and UB: P < 0.05, 80 µM UA and UB: P < 0.01). On the other hand, UA and UB significantly inhibited organoid development/outgrowth (40 and 80 µM UA: P < 0.0001 both; 40 µM UB: P < ns-0.05-0.001, and 80 µM UB: P < 0.01-0.001-0.001), and all organoid lines show urolithins sensitivity resulting in decreasing viability (UA exhibited a mean IC50 of 33.93 µM, while UB exhibited a mean IC50 of 52.60 µM).

LARGE-SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This study was performed on in vitro endometriosis models.

WIDER IMPLICATIONS OF THE FINDINGS

These in vitro results provide new insights into the pathogenetic pathways affected by these compounds and mark their use as a potential new therapeutic strategy for the treatment of endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded EU MSCA-RISE-2015 project MOMENDO (691058). The authors have no conflicts of interest to declare.

Changes in fatigue, barriers, and predictors towards physical activity in advanced cancer patients over a period of 12 months-a comparative study

Purpose

Physical activity (PA) is recommended to improve advanced cancer patients’ (ACP) physical functioning, fatigue, and quality of life. Yet, little is known about ACPs’ attitude towards PA and its influence on fatigue and depressiveness over a longer period. This prospective, non-interventional cohort study examined ACPs’ fatigue, depression, motivation, and barriers towards PA before and after 12 months of treatment among ACP

Methods

Outpatients with incurable cancer receiving treatment at a German Comprehensive Cancer Center reporting moderate/severe weakness/tiredness during self-assessment via MIDOS II were enrolled. Fatigue (FACT-F), depression (PHQ-8), cancer-related parameters, self-assessed PA behavior, motivation for and barriers against PA were evaluated (T0). Follow-up data was acquired after 12 months (T1) using the same questionnaire.

Results

At follow-up, fatigue (p=0.017) and depressiveness (p=0.015) had increased in clinical relevant extent. Physically active ACP did not show significant progress of FACT-F (p=0.836) or PHQ-8 (p=0.799). Patient-reported barriers towards PA remained stable. Logistic regression analyses identified motivation as a positive predictor for PA at both time points (T0, β=2.152, p=0.017; T1, β =2.264, p=0.009). Clinically relevant depression was a negative predictor for PA at T0 and T1 (T0, β=−3.187, p=0.044; T1, β=−3.521, p=0.041).

Conclusion

Our findings emphasize the importance of psychological conditions in physical activity behavior of ACP. Since psychological conditions seem to worsen over time, early integration of treatment is necessary. By combining therapy approaches of cognitive behavioral therapy and exercise in interdisciplinary care programs, the two treatment options might reinforce each other and sustainably improve ACPs’ fatigue, physical functioning, and QoL.

Trial registration

German Register of Clinical Trials, DRKS00012514, registration date: 30.05.2017

Discovery of Small Molecule Drugs Targeting the Biogenesis of microRNA-155 for the Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that often leads to functional disorder in multiple organs, most often with symptoms related to skin lesions, cardiovascular disease and kidney damage. Although significant efforts have been made to find efficient therapies, it still remains uncured. Furthermore, the current therapy is often associated with adverse side effects and leads to a high economic burden for society. At Saverna Therapeutics, in collaboration with our partners, we initiated a lead discovery program that aims to modulate the biogenesis of miR-155. This non-coding RNA is upregulated in SLE patients and SLE mouse models. We used our drug discovery platform based on iterative fragment-based screening by nuclear magnetic resonance (NMR) and machine learning to identify ligands of pre-miR-155. After several iterations and chemical modifications, we have identified compounds that show structure-activity relationships in cellular assays. These inhibitors reduced the level of miR-155 as well as its associated inflammatory protein TNF α whereas the cells remained viable during exposure of the compounds.

Role of syndecan-1 in the interaction between dendritic cells and T cells

Syndecan-1 (Sdc-1) is a heparan sulfate proteoglycan that can bind cytokines and chemokines via its heparan sulfate side chains, and has immunomodulatory properties in experimental models. Sdc-1 expression has been reported on dendritic cells (DC) and T cells. The potential role of Sdc-1 in DC-T cell interaction has not been investigated yet. We postulate that Sdc-1 is involved in DC-T cell interaction and may influence graft survival in an allogeneic transplant model. Sdc-1 expression on bone marrow-derived DC and T cells was analyzed by flow cytometry. Unstimulated and LPS stimulated Sdc-1 deficient DC were evaluated in vitro for phenotype and stimulatory capacity in mixed lymphocyte reaction. Sdc-1 deficient T cells were evaluated for proliferative capacity and differentiation in a mixed lymphocyte reaction and a proliferation assay. Allograft survival was evaluated in a fully MHC mismatched heterotopic heart transplant model, with either Sdc-1 deficient donors or recipients. Sdc-1 was expressed on the cell surface of unstimulated and LPS matured DC. Sdc-1 deficiency had no effect on expression of co-stimulatory molecules, cytokine production or T cell stimulatory capacity as compared to WT DC. Sdc-1 expression was not detectable on WT T cells, although intracellular Sdc-1 expression could be demonstrated after ConA activation. Sdc-1 deficient T cells showed reduced proliferation upon DC or ConA stimulation and reduced IL-17 production upon ConA stimulation, compared to WT T cells. Sdc-1 deficiency of either allograft or recipient did not prolong allograft survival. In conclusion, Sdc-1 is expressed on the cell surface of DC, where its absence does not affect DC phenotype or T cell stimulatory capacity. Sdc-1 is intracellularly expressed in ConA activated T cells. Sdc-1 deficiency in T cells results in a reduced proliferative response in vitro, as induced by DC and ConA. Sdc-1 deficiency in donor or recipient does not affect allograft survival.

Fatigue, barriers to physical activity and predictors for motivation to exercise in advanced Cancer patients

Background

In order to counteract fatigue, physical activity (PA) is recommended for all stages of cancer. However, only few advanced cancer patients (ACP) are physically active. Quantitative data with high numbers of ACP reporting barriers to PA are missing. This study aimed to identify barriers to PA in ACP with tiredness/weakness and investigate their motivation towards it.

Methods

Outpatients with metastatic cancer receiving cancer care at a German Cancer Center reporting moderate/severe tiredness/weakness during self-assessment (MIDOS II) were enrolled. We assessed Fatigue-(FACF-F) and Depression (PHQ8) Scores, demographics, cancer-specific parameters, motivation for PA, physical, psychological and social barriers.

Results

141 of 440 eligible patients (32.0%) with different diagnoses agreed to participate. Patients frequently reported “I feel weakened due to my tumor therapy” (n = 108; 76.6%), physical symptoms (tiredness, weakness, dyspnea, joint-problems, pain, nausea [n = 107; 75.9%]) and fatigue (n = 99; 70.2%) as barriers to PA. However, no significant group differences regarding these barriers were found between physically active and inactive patients. Social barriers were rarely chosen. Motivated patients were 5.6 times more likely to be physically active (p < 0.001), also motivation turned out to be the strongest predictor for a physically active behavior (β = 1.044; p = 0.005). Motivated attitude towards PA was predicted by fatigue (β = − 2.301; p = 0.008), clinically relevant depression (β = − 1.390, p = 0.039), knowledge about PA and quality of life (QoL) (β = 0.929; p = 0.002), PA before diagnosis (β = 0.688; p = 0.005 and Interest in exercise program (β = 0.635; p = 0.008).

Conclusion

“I feel weakened due to my tumor therapy” is the most reported barrier to PA among both, physically and inactive patients. Motivation for PA is the strongest predictor of performing PA. Interest in PA, knowledge about PA/QoL and PA before diagnosis are main predictors of a motivated attitude. Absence/presence of social barriers did not associate with motivation, fatigue and depression proved to be a negative predictor. Programs including information, motivational counseling and individualized training should be offered for ACP to overcome barriers and reduce fatigue.

Trial registration

German Register of Clinical Trials DRKS00012514, registration date: 30.5.2017.

Pharmacologic interventions for fatigue in cancer and transplantation: a meta-analysis

Background

Our objective was to determine whether, compared with control interventions, pharmacologic interventions reduce the severity of fatigue in patients with cancer or recipients of hematopoietic stem-cell transplantation (hsct).

Methods

For a systematic review, we searched medline, embase, the Cochrane Central Register of Controlled Trials, cinahl, and Psychinfo for randomized trials of systemic pharmacologic interventions for the management of fatigue in patients with cancer or recipients of hsct. Two authors independently identified studies and abstracted data. Methodologic quality was assessed using the Cochrane Risk of Bias tool. The primary outcome was fatigue severity measured using various fatigue scales. Data were synthesized using random-effects models.

Results

In the 117 included trials (19,819 patients), the pharmacologic agents used were erythropoietins (n = 31), stimulants (n = 19), l-carnitine (n = 6), corticosteroids (n = 5), antidepressants (n = 5), appetite stimulants (n = 3), and other agents (n = 48). Fatigue was significantly reduced with erythropoietin [standardized mean difference (smd): -0.52; 95% confidence interval (ci): -0.89 to -0.14] and with methylphenidate (smd: -0.36; 95% ci: -0.56 to -0.15); modafinil (or armodafinil) and corticosteroids were not effective.

Conclusions

Erythropoietin and methylphenidate significantly reduced fatigue severity in patients with cancer and in recipients of hsct. Concerns about the safety of those agents might limit their usefulness. Future research should identify effective interventions for fatigue that have minimal adverse effects.

Identification of SPPL2a Inhibitors by Multiparametric Analysis of a High-Content Ultra-High-Throughput Screen

The intramembrane protease signal peptide peptidase-like 2a (SPPL2a) is a potential drug target for the treatment of autoimmune diseases due to an essential role in B cells and dendritic cells. To screen a library of 1.4 million compounds for inhibitors of SPPL2a, we developed an imaging assay detecting nuclear translocation of the proteolytically released cytosolic substrate fragment. The state-of-the-art hit calling approach based on nuclear translocation resulted in numerous false-positive hits, mainly interrupting intracellular protein trafficking. To filter the false positives, we extracted 340 image-based readouts and developed a novel multiparametric analysis method that successfully triaged the primary hit list. The identified scaffolds were validated by demonstrating activity on endogenous SPPL2a and substrate CD74/p8 in B cells. The multiparametric analysis discovered diverse cellular phenotypes and provided profiles for the whole library. The principle of the presented imaging assay, the screening strategy, and multiparametric analysis are potentially applicable in future screening campaigns.

Tachyarrhythmia in patients with congenital heart disease: inevitable destiny?

The prevalence of patients with congenital heart disease (CHD) has increased over the last century. As a result, the number of CHD patients presenting with late, postoperative tachyarrhythmias has increased as well. The aim of this review is to discuss the present knowledge on the mechanisms underlying both atrial and ventricular tachyarrhythmia in patients with CHD and the advantages and disadvantages of the currently available invasive treatment modalities.

Discovery of Novel Allosteric Non-Bisphosphonate Inhibitors of Farnesyl Pyrophosphate Synthase by Integrated Lead Finding

Farnesyl pyrophosphate synthase (FPPS) is an established target for the treatment of bone diseases, but also shows promise as an anticancer and anti-infective drug target. Currently available anti-FPPS drugs are active-site-directed bisphosphonate inhibitors, the peculiar pharmacological profile of which is inadequate for therapeutic indications beyond bone diseases. The recent discovery of an allosteric binding site has paved the way toward the development of novel non-bisphosphonate FPPS inhibitors with broader therapeutic potential, notably as immunomodulators in oncology. Herein we report the discovery, by an integrated lead finding approach, of two new chemical classes of allosteric FPPS inhibitors that belong to the salicylic acid and quinoline chemotypes. We present their synthesis, biochemical and cellular activities, structure-activity relationships, and provide X-ray structures of several representative FPPS complexes. These novel allosteric FPPS inhibitors are devoid of any affinity for bone mineral and could serve as leads to evaluate their potential in none-bone diseases.

Physicochemical and biological characterization of chitosan-microRNA nanocomplexes for gene delivery to MCF-7 breast cancer cells

Cancer gene therapy requires the design of non-viral vectors that carry genetic material and selectively deliver it with minimal toxicity. Non-viral vectors based on cationic natural polymers can form electrostatic complexes with negatively-charged polynucleotides such as microRNAs (miRNAs). Here we investigated the physicochemical/biophysical properties of chitosan-hsa-miRNA-145 (CS-miRNA) nanocomplexes and the biological responses of MCF-7 breast cancer cells cultured in vitro. Self-assembled CS-miRNA nanocomplexes were produced with a range of (+/-) charge ratios (from 0.6 to 8) using chitosans with various degrees of acetylation and molecular weight. The Z-average particle diameter of the complexes was <200 nm. The surface charge increased with increasing amount of chitosan. We observed that chitosan induces the base-stacking of miRNA in a concentration dependent manner. Surface plasmon resonance spectroscopy shows that complexes formed by low degree of acetylation chitosans are highly stable, regardless of the molecular weight. We found no evidence that these complexes were cytotoxic towards MCF-7 cells. Furthermore, CS-miRNA nanocomplexes with degree of acetylation 12% and 29% were biologically active, showing successful downregulation of target mRNA expression in MCF-7 cells. Our data, therefore, shows that CS-miRNA complexes offer a promising non-viral platform for breast cancer gene therapy.

Importance of transvaginal ultrasound applying elastography for identifying deep infiltrating endometriosis - a feasibility study

PURPOSE

To evaluate the presence of a lesion indicative of endometriosis with transvaginal elastography.

MATERIALS AND METHODS

Transvaginal ultrasound and clinical examination were carried out in 48 women with clinical symptoms indicative of endometriosis. In 31 cases strain values were measured at two regions of interest (ROIs) in the Douglas's cul-de-sac during a cycle of compression and decompression with a vaginal probe.

RESULTS

A significant difference was found for the ratio of the ROI measuring points in the Douglas' cul-de-sacs of women with a palpable nodule in examination compared to women without a palpable nodule (p = 0.002).

CONCLUSION

The ratio of strain values between two ROIs in the Douglas' s cul-de-sac is associated with the presence of an endometriotic lesion. In the future, these findings could allow for a more detailed pre-surgical evaluation and possibly serve as a novel diagnostic tool for predicting deep infiltrating endometriosis.

Characterization of amino acids Arg, Ser and Thr at position 70 within HIV-1 reverse transcriptase

OBJECTIVES

The amino acid position 70 in HIV-1 reverse transcriptase (RT) plays an important role in nucleoside RT inhibitor (NRTI) resistance. K70R is part of the thymidine analog mutations, but also other amino acid changes have been associated with NRTI resistance, such as K70E and K70G. In this study, we investigated the in vivo selection of the HIV-1 RT mutations K70S and K70T and their in vitro effect on drug resistance and replication capacity.

METHODS

Recombinant viruses with RT mutations were generated to measure the in vitro drug susceptibility and replication capacity. Bayesian network analysis and three-dimensional modeling were performed to understand the selection and impact of the RT70 mutations.

RESULTS

K70S and K70T were found at a low frequency in RTI-experienced HIV-1 patients (0.10% and 0·20%). Baeyesian network learning identified no direct association with the in vivo exposure to any specific RTI. However, direct associations of K70S with mutations within the Q151M-complex and of K70T with K65R were observed. In vitro phenotypic testing revealed only minor effects of K70R/S/T as single mutations, associated with Q151M and within the context of the Q151M-complex.

DISCUSSION

These results suggest that the selection of K70S/T and their phenotypic impact are influenced by the presence of other mutations in RT. However, the low impact on in vitro phenotype here observed, alongside with the low in vivo prevalence, the exclusive direct association with known major RTI mutations and the unknown correlation with in vivo response, do not yet necessitate the inclusion of K70S/T in drug resistance interpretation systems.

MOON-test - determination of motor performance in the pediatric oncology

BACKGROUND

Pediatric cancer patients suffer from various negative consequences due to the disease, the medical therapy and the inactivity during the intensive treatment. Only few studies have systematically identified the adverse effects of cancer on motor performance in childhood.

METHODS

To determine the motor performance of pediatric cancer patients, a motor performance test was developed which is applicable for this specific patient group. Eight test items with reference values for healthy children were merged to the MOON-test (test for motor performance in the oncology).

RESULTS

MOON was tested for feasibility and acceptance in 33 patients aged 4-18 years. Feasibility was confirmed for children with different types of cancer (hematological malignancies and solid tumors) and with amputation, endoprosthesis, during aplasia as well as reduced general condition. Furthermore the patients showed a broad acceptance.

CONCLUSION

Based on the study findings, the use of MOON-test as a standardized motor performance diagnostic tool in clinical routine of oncological acute clinics as well as rehabilitation clinics can be recommended.·

Survivin, a target to modulate the radiosensitivity of Ewing's sarcoma

BACKGROUND AND PURPOSE

Radiotherapy constitutes an essential element in the multimodal therapy of Ewing's sarcoma. Compared to other sarcomas, Ewing tumors normally show a good response to radiotherapy. However, there are consistently tumors with a radioresistant phenotype, and the underlying mechanisms are not known in detail. Here we investigated the association between survivin protein expression and the radiosensitivity of Ewing's sarcoma in vitro.

MATERIAL AND METHODS

An siRNA-based knockdown approach was used to investigate the influence of survivin expression on cell proliferation, double-strand break (DSB) induction and repair, apoptosis and colony-forming ability in four Ewing's sarcoma cell lines with and without irradiation.

RESULTS

Survivin protein and mRNA were upregulated in all cell lines tested in a dose-dependent manner. As a result of survivin knockdown, STA-ET-1 cells showed reduced cell proliferation, an increased number of radiation-induced DSBs, and reduced repair. Apoptosis was increased by knockdown alone and increased further in combination with irradiation. Colony formation was significantly reduced by survivin knockdown in combination with irradiation.

CONCLUSION

Survivin is a radiation-inducible protein in Ewing's sarcoma and its down-regulation sensitizes cells toward irradiation. Survivin knockdown in combination with radiation inhibits cell proliferation, repair, and colony formation significantly and increases apoptosis more than each single treatment alone. This might open new perspectives in the radiation treatment of Ewing's sarcoma.

Differentiation and visualization of diverse cellular phenotypic responses in primary high-content screening

High-throughput screening, based on subcellular imaging, has become a powerful tool in lead discovery. Through the generation of high-quality images, not only the specific target signal can be analyzed but also phenotypic changes of the whole cell are recorded. Yet analysis strategies for the exploration of high-content screening results, in a manner that is independent from predefined control phenotypes, are largely missing. The approach presented here is based on a well-established modeling technique, self-organizing maps (SOMs), which uses multiparametric results to group treatments that create similar morphological effects. This report describes a novel visualization of the SOM clustering by using an image of the cells from each node, with the most representative cell highlighted to deploy the phenotype described by each node. The approach has the potential to identify both expected hits and novel cellular phenotypes. Moreover, different chemotypes, which cause the same phenotypic effects, are identified, thus facilitating "scaffold hopping."

mRNA-expression of ERα, ERβ, and PR in clonal stem cell cultures obtained from human endometrial biopsies

Background. Proliferation and differentiation of the endometrium are regulated by estrogen and progesterone. The enormous regenerative capacity of the endometrium is thought to be based on the activity of adult stem cells. However, information on endocrine regulatory mechanisms in human endometrial stem cells is scarce. In the present study, we investigated the expression of ERα, ERβ, and PR in clonal cultures of human endometrial stem cells derived from transcervical biopsies. Methods. Endometrial tissue of 11 patients was obtained by transcervical biopsy. Stromal cell suspensions were plated at clonal density and incubated for 15 days. Expression of ERα, ERβ and PR was determined by qPCR prior to and after one cloning round, and normalized to 18 S rRNA expression. Results. Expression of ERα and ERβ was downregulated by 64% and 89%, respectively (P = 0.002 and P < 0.001). In contrast, PR was not significantly downregulated, due to a more heterogenous expression pattern. Conclusions. Culture of human endometrial stroma cells results in a downregulation of ERα and ERβ, while expression of PR remained unchanged in our patient collective. These results support the hypothesis that stem cells may not be subject to direct stimulation by sex steroids, but rather by paracrine mechanisms within the stem cell niche.