The Lipid Metabolism as Target and Modulator of BOLD-100 Anticancer Activity: Crosstalk with Histone Acetylation

The leading first-in-class ruthenium-complex BOLD-100 currently undergoes clinical phase-II anticancer evaluation. Recently, BOLD-100 is identified as anti-Warburg compound. The present study shows that also deregulated lipid metabolism parameters characterize acquired BOLD-100-resistant colon and pancreatic carcinoma cells. Acute BOLD-100 treatment reduces lipid droplet contents of BOLD-100-sensitive but not -resistant cells. Despite enhanced glycolysis fueling lipid accumulation, BOLD-100-resistant cells reveal diminished lactate secretion based on monocarboxylate transporter 1 (MCT1) loss mediated by a frame-shift mutation in the MCT1 chaperone basigin. Glycolysis and lipid catabolism converge in the production of protein/histone acetylation substrate acetyl-coenzymeA (CoA). Mass spectrometric and nuclear magnetic resonance analyses uncover spontaneous cell-free BOLD-100-CoA adduct formation suggesting acetyl-CoA depletion as mechanism bridging BOLD-100-induced lipid metabolism alterations and histone acetylation-mediated gene expression deregulation. Indeed, BOLD-100 treatment decreases histone acetylation selectively in sensitive cells. Pharmacological targeting confirms histone de-acetylation as central mode-of-action of BOLD-100 and metabolic programs stabilizing histone acetylation as relevant Achilles' heel of acquired BOLD-100-resistant cell and xenograft models. Accordingly, histone gene expression changes also predict intrinsic BOLD-100 responsiveness. Summarizing, BOLD-100 is identified as epigenetically active substance acting via targeting several onco-metabolic pathways. Identification of the lipid metabolism as driver of acquired BOLD-100 resistance opens novel strategies to tackle therapy failure.

Multiparametric Tissue Characterization Utilizing the Cellular Metallome and Immuno-Mass Spectrometry Imaging

In this study, we present a workflow that enables spatial single-cell metallomics in tissue decoding the cellular heterogeneity. Low-dispersion laser ablation in combination with inductively coupled plasma time-of-flight mass spectrometry (LA-ICP-TOFMS) provides mapping of endogenous elements with cellular resolution at unprecedented speed. Capturing the heterogeneity of the cellular population by metals only is of limited use as the cell type, functionality, and cell state remain elusive. Therefore, we expanded the toolbox of single-cell metallomics by integrating the concepts of imaging mass cytometry (IMC). This multiparametric assay successfully utilizes metal-labeled antibodies for cellular tissue profiling. One important challenge is the need to preserve the original metallome in the sample upon immunostaining. Therefore, we studied the impact of extensive labeling on the obtained endogenous cellular ionome data by quantifying elemental levels in consecutive tissue sections (with and without immunostaining) and correlating elements with structural markers and histological features. Our experiments showed that the elemental tissue distribution remained intact for selected elements such as sodium, phosphorus, and iron, while absolute quantification was precluded. We hypothesize that this integrated assay not only advances single-cell metallomics (enabling to link metal accumulation to multi-dimensional characterization of cells/cell populations), but in turn also enhances selectivity in IMC, as in selected cases, labeling strategies can be validated by elemental data. We showcase the power of this integrated single-cell toolbox using an in vivo tumor model in mice and provide mapping of the sodium and iron homeostasis as linked to different cell types and function in mouse organs (such as spleen, kidney, and liver). Phosphorus distribution maps added structural information, paralleled by the DNA intercalator visualizing the cellular nuclei. Overall, iron imaging was the most relevant addition to IMC. In tumor samples, for example, iron-rich regions correlated with high proliferation and/or located blood vessels, which are key for potential drug delivery.

Trabectedin Is Active against Two Novel, Patient-Derived Solitary Fibrous Pleural Tumor Cell Lines and Synergizes with Ponatinib

Solitary fibrous tumor of the pleura (SFT) is a rare disease. Besides surgery combined with radiotherapy in nondisseminated stages, curative options are currently absent. Out of fourteen primo-cell cultures, established from surgical SFT specimens, two showed stable in vitro growth. Both cell models harbored the characteristic NAB2-STAT6 fusion and were further investigated by different preclinical methods assessing cell viability, clone formation, and protein regulation upon single-drug treatment or in response to selected treatment combinations. Both fusion-positive cell models showed-in line with the clinical experience and the literature-a low to moderate response to most of the tested cytotoxic and targeted agents. However, the multi-tyrosine kinase inhibitors ponatinib and dasatinib, as well as the anti-sarcoma compound trabectedin, revealed promising activity against SFT growth. Furthermore, both cell models spontaneously presented strong FGFR downstream signaling targetable by ponatinib. Most interestingly, the combination of either ponatinib or dasatinib with trabectedin showed synergistic effects. In conclusion, this study identified novel trabectedin-based treatment combinations with clinically approved tyrosine kinase inhibitors, using two newly established NAB2-STAT6 fusion-positive cell models. These findings can be the basis for anti-SFT drug repurposing approaches in this rare and therapy-refractory disease.

Thermodynamic Genome-Scale Metabolic Modeling of Metallodrug Resistance in Colorectal Cancer

Simple Summary

Cancer, but also its treatment, can lead to a reprogramming of cellular metabolism. These changes are observable in metabolite abundances, which can be unbiasedly measured via mass spectrometry metabolomics. However, even when the metabolome changes strongly, a (mechanistic) interpretation is difficult as metabolite levels do not necessarily directly correspond to pathway activities. Here we measure the changes of the cellular metabolome in colorectal cancer cell lines sensitive and resistant to the ruthenium-based drug BOLD-100/KP1339 and the platinum-based drug oxaliplatin. We map these changes onto a cancer-specific genome-scale metabolic model, which allows us not only to compute intracellular flux distributions, but also to disentangle drug-specific effects from growth differences from differences in metabolic adaptations due to resistance. Specifically, we find that resistance to BOLD-100/KP1339 induces more extensive reprogramming than oxaliplatin, especially with respect to fatty acid and amino acid metabolism.

Abstract

Background: Mass spectrometry-based metabolomics approaches provide an immense opportunity to enhance our understanding of the mechanisms that underpin the cellular reprogramming of cancers. Accurate comparative metabolic profiling of heterogeneous conditions, however, is still a challenge. Methods: Measuring both intracellular and extracellular metabolite concentrations, we constrain four instances of a thermodynamic genome-scale metabolic model of the HCT116 colorectal carcinoma cell line to compare the metabolic flux profiles of cells that are either sensitive or resistant to ruthenium- or platinum-based treatments with BOLD-100/KP1339 and oxaliplatin, respectively. Results: Normalizing according to growth rate and normalizing resistant cells according to their respective sensitive controls, we are able to dissect metabolic responses specific to the drug and to the resistance states. We find the normalization steps to be crucial in the interpretation of the metabolomics data and show that the metabolic reprogramming in resistant cells is limited to a select number of pathways. Conclusions: Here, we elucidate the key importance of normalization steps in the interpretation of metabolomics data, allowing us to uncover drug-specific metabolic reprogramming during acquired metal-drug resistance.

Die Wechselwirkung mit ribosomalen Proteinen begleitet die Stressinduktion des Wirkstoffkandidaten BOLD-100/KP1339 im endoplasmatischen Retikulum

Der metallhaltige Wirkstoff BOLD‐100/KP1339 zeigte bereits vielversprechende Resultate in verschiedenen In vitro‐ und In vivo‐Tumormodellen sowie in klinischen Studien. Der detaillierte Wirkmechanismus wurde jedoch noch nicht komplett aufgeklärt. Als entscheidende Wirkstoffeffekte kristallisierten sich kürzlich die Stressinduktion im endoplasmatischen Retikulum (ER) und die damit einhergehende Modulierung von HSPA5 (GRP78) heraus. Das spontane und stabile Addukt zwischen BOLD‐100 und menschlichem Serumalbumin wurde als Immobilisierungsstrategie ausgewählt, um einen chemoproteomischen Ansatz auszuführen, der die ribosomalen Proteine RPL10, RPL24 und den Transkriptionsfaktor GTF2I als potentielle Interaktoren dieser Ru(III)‐Verbindung identifizierten. Dieses Ergebnis wurde mit proteomischen und transkriptomischen Profiling‐Experimenten kombiniert, was die Interpretation einer ribosomalen Beeinträchtigung sowie der Induktion von ER‐Stress unterstützte. Die Bildung von Polyribosomen und begleitende ER‐Schwellungen in behandelten Krebszellen wurden zudem durch TEM‐Messungen bestätigt. Somit scheint eine direkte Wechselwirkung von BOLD‐100 mit ribosomalen Proteinen die ER‐Stressinduktion und die Modulierung von GRP78 in Krebszellen zu begleiten.

Interaction with Ribosomal Proteins Accompanies Stress Induction of the Anticancer Metallodrug BOLD-100/KP1339 in the Endoplasmic Reticulum

The ruthenium-based anticancer agent BOLD-100/KP1339 has shown promising results in several in vitro and in vivo tumour models as well as in early clinical trials. However, its mode of action remains to be fully elucidated. Recent evidence identified stress induction in the endoplasmic reticulum (ER) and concomitant down-modulation of HSPA5 (GRP78) as key drug effects. By exploiting the naturally formed adduct between BOLD-100 and human serum albumin as an immobilization strategy, we were able to perform target-profiling experiments that revealed the ribosomal proteins RPL10, RPL24, and the transcription factor GTF2I as potential interactors of this ruthenium(III) anticancer agent. Integrating these findings with proteomic profiling and transcriptomic experiments supported ribosomal disturbance and concomitant induction of ER stress. The formation of polyribosomes and ER swelling of treated cancer cells revealed by TEM validated this finding. Thus, the direct interaction of BOLD-100 with ribosomal proteins seems to accompany ER stress-induction and modulation of GRP78 in cancer cells.

124 I Radiolabeling of a AuIII -NHC Complex for In Vivo Biodistribution Studies

AuIII complexes with N-heterocyclic carbene (NHC) ligands have shown remarkable potential as anticancer agents, yet their fate in vivo has not been thoroughly examined and understood. Reported herein is the synthesis of new AuIII -NHC complexes by direct oxidation with radioactive [124 I]I2 as a valuable strategy to monitor the in vivo biodistribution of this class of compounds using positron emission tomography (PET). While in vitro analyses provide direct evidence for the importance of AuIII -to-AuI reduction to achieve full anticancer activity, in vivo studies reveal that a fraction of the AuIII -NHC prodrug is not immediately reduced after administration but able to reach the major organs before metabolic activation.

Lipid droplet-mediated scavenging as novel intrinsic and adaptive resistance factor against the multikinase inhibitor ponatinib

Ponatinib is a small molecule multi‐tyrosine kinase inhibitor clinically approved for anticancer therapy. Molecular mechanisms by which cancer cells develop resistance against ponatinib are currently poorly understood. Likewise, intracellular drug dynamics, as well as potential microenvironmental factors affecting the activity of this compound are unknown. Cell/molecular biological and analytical chemistry methods were applied to investigate uptake kinetics/subcellular distribution, the role of lipid droplets (LDs) and lipoid microenvironment compartments in responsiveness of FGFR1‐driven lung cancer cells toward ponatinib. Selection of lung cancer cells for acquired ponatinib resistance resulted in elevated intracellular lipid levels. Uncovering intrinsic ponatinib fluorescence enabled dissection of drug uptake/retention kinetics in vitro as well as in mouse tissue cryosections, and revealed selective drug accumulation in LDs of cancer cells. Pharmacological LD upmodulation or downmodulation indicated that the extent of LD formation and consequent ponatinib incorporation negatively correlated with anticancer drug efficacy. Co‐culturing with adipocytes decreased ponatinib levels and fostered survival of cancer cells. Ponatinib‐selected cancer cells exhibited increased LD levels and enhanced ponatinib deposition into this organelle. Our findings demonstrate intracellular deposition of the clinically approved anticancer compound ponatinib into LDs. Furthermore, increased LD biogenesis was identified as adaptive cancer cell‐defense mechanism via direct drug scavenging. Together, this suggests that LDs represent an underestimated organelle influencing intracellular pharmacokinetics and activity of anticancer tyrosine kinase inhibitors. Targeting LD integrity might constitute a strategy to enhance the activity not only of ponatinib, but also other clinically approved, lipophilic anticancer therapeutics.

What's new?

Ponatinib is a small‐molecule multi‐tyrosine kinase inhibitor clinically approved for anticancer therapy. However, to date, the intracellular pharmacokinetics of this compound and the molecular mechanisms underlying resistance in cancer cells remain largely unknown. Here, the authors found that ponatinib was selectively scavenged by lipid droplets in cancer cells. Ponatinib accumulation into lipid droplets emerged as a critical determinant of intrinsic and acquired drug resistance. The findings suggest that lipid droplets represent an underestimated organelle influencing intracellular pharmacokinetics and anticancer tyrosine kinase inhibitor activity. Moreover, co‐targeting of lipogenic cancer cell phenotypes might enhance the efficacy of ponatinib and other lipophilic pharmaceuticals.

Ruthenium-arene complexes bearing naphthyl-substituted 1,3-dioxoindan-2-carboxamides ligands for G-quadruplex DNA recognition

Quadruplex nucleic acids - DNA/RNA secondary structures formed in guanine rich sequences - proved to have key roles in the biology of cancers and, as such, in recent years they emerged as promising targets for small molecules. Many reports demonstrated that metal complexes can effectively stabilize quadruplex structures, promoting telomerase inhibition, downregulation of the expression of cancer-related genes and ultimately cancer cell death. Although extensively explored as anticancer agents, studies on the ability of ruthenium arene complexes to interact with quadruplex nucleic acids are surprisingly almost unknown. Herein, we report on the synthesis and characterization of four novel Ru(ii) arene complexes with 1,3-dioxoindan-2-carboxamides ligands bearing pendant naphthyl-groups designed to bind quadruplexes by both stacking and coordinating interactions. We show how improvements on the hydrolytic stability of such complexes, by substituting the chlorido leaving ligand with pyridine, have a dramatic impact on their interaction with quadruplexes and on their cytotoxicity against ovarian cancer cells.

Challenges and Chances in the Preclinical to Clinical Translation of Anticancer Metallodrugs

Despite being “sentenced to death” for quite some time, anticancer platinum compounds are still the most frequently prescribed cancer therapies in the oncological routine and recent exciting news from late-stage clinical studies on combinations of metallodrugs with immunotherapies suggest that this situation will not change soon. It is perhaps surprising that relatively simple molecules like cisplatin, discovered over 50 years ago, are still widely used clinically, while none of the highly sophisticated metal compounds developed over the last decade, including complexes with targeting ligands and multifunctional (nano)formulations, have managed to obtain clinical approval. In this book chapter, we summarize the current status of ongoing clinical trials for anticancer metal compounds and discuss the reasons for previous failures, as well as new opportunities for the clinical translation of metal complexes.

Altered membrane rigidity via enhanced endogenous cholesterol synthesis drives cancer cell resistance to destruxins

Destruxins, secondary metabolites of entomopathogenic fungi, exert a wide variety of interesting characteristics ranging from antiviral to anticancer effects. Although their mode of action was evaluated previously, the molecular mechanisms of resistance development are unknown. Hence, we have established destruxin-resistant sublines of HCT116 colon carcinoma cells by selection with the most prevalent derivatives, destruxin (dtx)A, dtxB and dtxE. Various cell biological and molecular techniques were applied to elucidate the regulatory mechanisms underlying these acquired and highly stable destruxin resistance phenotypes. Interestingly, well-known chemoresistance-mediating ABC efflux transporters were not the major players. Instead, in dtxA- and dtxB-resistant cells a hyper-activated mevalonate pathway was uncovered resulting in increased de-novo cholesterol synthesis rates and elevated levels of lanosterol, cholesterol as well as several oxysterol metabolites. Accordingly, inhibition of the mevalonate pathway at two different steps, using either statins or zoledronic acid, significantly reduced acquired but also intrinsic destruxin resistance. Vice versa, cholesterol supplementation protected destruxin-sensitive cells against their cytotoxic activity. Additionally, an increased cell membrane adhesiveness of dtxA-resistant as compared to parental cells was detected by atomic force microscopy. This was paralleled by a dramatically reduced ionophoric capacity of dtxA in resistant cells when cultured in absence but not in presence of statins. Summarizing, our results suggest a reduced ionophoric activity of destruxins due to cholesterol-mediated plasma membrane re-organization as molecular mechanism underlying acquired destruxin resistance in human colon cancer cells. Whether this mechanism might be valid also in other cell types and organisms exposed to destruxins e.g. as bio-insecticides needs to be evaluated.

Targeting a Targeted Drug: An Approach Toward Hypoxia-Activatable Tyrosine Kinase Inhibitor Prodrugs

Tyrosine kinase inhibitors (TKIs), which have revolutionized cancer therapy over the past 15 years, are limited in their clinical application due to serious side effects. Therefore, we converted two approved TKIs (sunitinib and erlotinib) into 2-nitroimidazole-based hypoxia-activatable prodrugs. Kinetics studies showed very different stabilities over 24 h; however, fast reductive activation via E. coli nitroreductase could be confirmed for both panels. The anticancer activity and signaling inhibition of the compounds against various human cancer cell lines were evaluated in cell culture. These data, together with molecular docking simulations, revealed distinct differences in the impact of structural modifications on drug binding to the enzymes: whereas the catalytic pocket of the epidermal growth factor receptor (EGFR) accepted all new erlotinib derivatives, the vascular endothelial growth factor receptor (VEGFR)-inhibitory potential in the case of the sunitinib prodrugs was dramatically diminished by derivatization. In line, hypoxia dependency of ERK signaling inhibition was observed with the sunitinib prodrugs, while oxygen levels had no impact on the activity of the erlotinib derivatives. Overall, proof of principle could be shown for this concept, and the results obtained are an important basis for the future development of tyrosine kinase inhibitor prodrugs.

Pressure shift freezing as potential alternative for generation of decellularized scaffolds

Background. Protocols using chemical reagents for scaffold decellularization can cause changes in the properties of the matrix, depending on the type of tissue and the chemical reagent. Technologies using physical techniques may be possible alternatives for the production grafts with potential superior matrix characteristics. Material and Methods. We tested four different technologies for scaffold decellularization. Group 1: high hydrostatic pressure (HHP), 1 GPa; Group 2: pressure shift freezing (PSF); Group 3: pulsed electric fields (PEF); Group 4: control group: detergent (SDS). The degree of decellularization was assessed by histological analysis and the measurement of residual DNA. Results. Tissue treated with PSF showed a decellularization with a penetration depth (PD) of 1.5 mm and residual DNA content of 24% ± 3%. HHD treatment caused a PD of 0.2 mm with a residual DNA content of 28% ± .4%. PD in PEF was 0.5 mm, and the residual DNA content was 49% ± 7%. In the SDS group, PD was found to be 5 mm, and the DNA content was determined at 5% ± 2%. Conclusion. PSF showed promising results as a possible technique for scaffold decellularization. The penetration depth of PSF has to be optimized, and the mechanical as well as the biological characteristics of decellularized grafts have to be evaluated.

Aging of registered stem cell donors: implications for donor recruitment

With more than 11 million registered stem cell donors worldwide and limited resources for health systems, it seems questionable if investments in ongoing donor recruitment are useful. Since there is evidence that transplant outcomes are better with younger donors, the age distribution of registered donors is highly relevant in this context. One might argue that the usefulness of a donor file decreases if there is no new donor recruitment not only as a result of loss of donors who reach the age limit for donation but also since those donors who remain in the file get older. We established a multivariate model to quantify this effect and to estimate the number (designated R) of donors who must be recruited annually to keep donor file usefulness constant. The model is applied to real data from DKMS German Bone Marrow Donor Center. R exceeds the number of donors who reach the age limit by factors up to 7.3. The model can serve as an easy-to-use tool for strategic donor registry planning. Our results suggest that analyses regarding optimal size of donor registries should also include the age distribution of registered donors.

Selective recruitment of stem cell donors with rare human leukocyte antigen phenotypes

Many patients in need of a hematopoietic stem cell transplant do not find a fully matching donor although more than 11,000,000 potential donors are registered worldwide. Therefore, it is relevant to recruit donors who add diversity to the donor pool. We present the 'Roots' approach that includes the selection of already registered donors with rare HLA phenotypes and the recruitment of relatives of these donors. Two projects (Roots A and B) with different donor selection criteria were carried out. HLA phenotype frequency distributions of new donors differ significantly from the respective control groups: 2.7% of Roots A donors versus 1.1% of the control group have an HLA-AB phenotype that is unique in the DKMS file (P=0.001). Additionally, 39.5% of Roots B donors but only 18.3% of the control group have a unique HLA-ABDR phenotype (P<0.001). Similar results are found when phenotypes that are at most available 10 times in the DKMS donor file are analyzed. The results show that the Roots approach is generally suited to increasing the ratio of donors with rare HLA phenotypes in a donor file. Additional costs of Roots donor recruitment seem justified through the ratio of recruited donors with rare HLA phenotypes.

[Topographical anatomy of the female pelvis in ultrasound]

AIM

Achieving a high quality gynaecological ultrasound examination requires thorough knowledge of topographic anatomy. To date, there are no guidelines for a standardised course of the examination. The goal of the study was to define exact planes by means of cross-sectional anatomy and then to standardise the gynaecological ultrasound examination with the transabdominal, introital and transvaginal technique.

METHOD

We developed a software tool based on IDL (Interactive Data Language) for the female data set of the Visible Human Project which generates free determinable planes in the volume. The organs of the female pelvis were divided into landmark- and target structures according to the ultrasonic visibility and the variability of the position, shape and structure. From this, a course for the gynaecological ultrasound examination was created and verified on 65 patients each with an inconspicuous ultrasound finding. In addition, the average duration of the examination was determined.

RESULTS

The landmark structures could be demonstrated in all patients. Five planes were defined for each technique, and the course of the whole examination with 15 exact planes was described. The average duration of the examination was 4.5 minutes.

CONCLUSION

As of now, the digitally reconstructed anatomical illustrations have achieved the best image resolution and quality regardless of the position of the plane in the examination volume. The standardised course of the gynaecological ultrasound examination can serve as a basis for the improvement of training quality and the evaluation of a general gynaecological ultrasound screening.

Expression of beta hCG and alpha CG mRNA and hCG hormone in human decidual tissue in patients during tubal pregnancy

We recently showed that endometrial tissue produces hCG during the secretory phase of the menstrual cycle. Based on these findings, we hypothesized that the decidua should also be able to secrete hCG. We examined the decidualized endometrium of patients with extrauterine pregnancies. Decidual specimens were obtained for mRNA extraction and paraffin embedding from 24 patients that were between weeks 6-11 of tubal pregnancy. Tissues were evaluated and classified into one of three groups based on the endometrial differentiation that took place prior to conception: (A) high secretory transformation, (B) diminished transformation with restricted decidualization and (C) inferior endometrial proliferation. Decidual gland hCG secretion was demonstrated immunohistochemically and by Western blotting. Serum hCG levels were higher (P < 0.0001) in patients from group A than group C. mRNA expression of both the beta subunit (beta-hCG) and alpha subunit (alpha-CG) was determined by RT-PCR. Furthermore, the specificity of beta-hCG amplification was confirmed by restriction enzymes. beta-LH amplification was not found. Moreover, the degree of endometrial transformation and the level of decidualization was found to correlate with hCG hormone staining and beta-hCG mRNA expression. hCG protein in the decidua was present in the glands of the compact layer and in the spongy layer, and was more pronounced in previously transformed high secretory endometrium than in inferior endometrium. In conclusion, this study provides the first evidence that hCG is produced in the decidua of patients during extrauterine pregnancies and might play a possible paracrine role.

Approaches to managing volunteer marrow donor registry HLA data. Algorithms for directing donor center-initiated HLA-DR typing of selected donors

The German bone marrow donor center (DKMS) hasrecruited over 732 500 donors during the first 9 years of its existence. Initially, donors were typed for HLA-A and B, and DR typing was only done on request for a patient-initiated search. In 1994, a project was started which led to the donor center-initiated DR typing (DCI-DRT) of >35,000 donors. These donors were selected by donor-specific criteria (age, sex, height and weight) and according to HLA-A and B phenotypes. The latter was done to avoid unnecessary DR typing of the most common A, B phenotypes With a follow up of >6 years, this strategy has led to a number of confirmatory typings (CT) (n=4588) and stem cell harvests (n=568), which is at least comparable to those ensuing after patient-initiated HLA-DR typing (126 000 DR typings, 8,213 CTs, 888 resulting in stem-cell donation). DCI-DRT seems to be a cost-effective strategy which may help to reduce search times and improve search outcome, and improve the overall efficiency of donor center operations

Cathepsin S and an asparagine-specific endoprotease dominate the proteolytic processing of human myelin basic protein in vitro

The biochemical characterization of antigen degradation is an important basis for a better understanding of both the immune response and autoimmune diseases mediated by MHC class II molecules. In this study we used high-performance liquid chromatography and mass spectrometry to analyze the processing of myelin basic protein (MBP), a potential autoantigen implicated in the pathogenesis of multiple sclerosis. We resolved the kinetics of MBP processing by lysosomal extracts or purified endocytic proteases, identified the major cleavage sites during this process and assigned them to the activity of proteolytic enzymes. Proteolytic processing of MBP is mostly guided along the hydrophobic regions of the protein. It is initiated by two proteolytic steps (after N(92) and S(110)) that are performed by an asparagine-specific endopeptidase (AEP) and by cathepsin (Cat) S, respectively. The resulting processing intermediates are converted into more than 60 different species of 20-40-mers due to the activity of endopeptidases including CatS, D and L. The fragments thus generated are subsequently degraded by C- or N-terminal trimming. Strikingly, the initial cleavages during MBP processing affect two immunodominant regions of the potential autoantigen [MBP(85-99) and MBP(111-129)] in an inverse manner. CatS directly generates the N terminus of the epitope MBP(111-129) in large quantities during the initial phase of processing, which might explain the immunogenicity of this region in spite of its relatively poor binding to HLA-DR4. In contrast, the dominant cleavage by AEP mediates the destruction of MBP(85-99) unless the epitope is protected, e.g. by binding to HLA-DR. Our results thus characterize the proteolytic events during processing of MBP on a molecular level and suggest a biochemical basis for the immunogenicity of the immunodominant epitopes, which could serve as a guideline for future therapeutic strategies.

[Myxoid uterine leiomyoma with focal lymphangioma-like pattern]

Myxoid leiomyomas of the uterus are uncommon. They are characterised by a myxoid stroma, no mitotic activity and a myogenic phenotype. We present a case with focal lymphangioma-like pattern. The solid compartiment showed positive immunoreactivity with muscular markers and but no CD 34-immunostaining. Contrary, the endothelial-like cells of the cystic part were positive with antibodies against CD 34, CD 31 and factor VIII, indicating vascular differentiation. The lack of infiltrative growth patterns excluded myxoid leiomyosarcoma as the major differenzial diagnosis.

Endometrial metastasis from breast cancer in a patient receiving tamoxifen therapy

Tamoxifen (TAM) is known to be associated with several types of endometrial pathologies, e.g. hyperplasias, polyps and endometrial carcinomas, sometimes of special histologic type. Here we report a rare case of endometrial metastasis from a breast carcinoma (ductal carcinoma) discovered during TAM therapy. This occurrence does not suggest that TAM treatment causes endometrial metastases of breast cancer. However, clinicians should be aware of this possibility and provide patients receiving TAM therapy with close gynecologic follow-up using liberal indications for endometrial biopsies.

Laparoscopic therapy of an intact primary ovarian pregnancy with ovarian hyperstimulation syndrome: case report

A case of an intact primary ovarian pregnancy with ultrasonographic demonstration of heart motion following ovarian stimulation is presented. After preoperative ultrasonographic confirmation of an extrauterine pregnancy, proof of the ovarian localization was achieved by intra-operative ultrasonographic visualization during a diagnostic laparoscopy on post-menstrual day 48. A moderate ovarian hyperstimulation syndrome with a concomitant increase in size, vulnerability and vascularity of the ovaries presented an additional challenge for the surgical approach. However, thanks to the early diagnosis of the ectopic pregnancy localization, a laparoscopic organ-preserving removal of the intact ovarian pregnancy was successfully performed. In this way, the fertility of the patient, who had previously undergone contralateral ovariectomy, was preserved. To our knowledge, this represents the first such treatment to be reported in the medical literature. Improvements in diagnosis and therapy of ovarian pregnancy are reviewed.

Comparison of moclobemide with selective serotonin reuptake inhibitors (SSRIs) on sexual function in depressed adults. The Australian and German Study Groups

OBJECTIVE

To compare the emergent sexual effects of moclobemide and selective serotonin reuptake inhibitors (SSRIs) during acute and maintenance therapy in routine practice.

METHOD

268 patients were evaluated for sexual function at baseline, 6 weeks, 3 and 6 months of treatment using physician ratings and self-rating questionnaires. Patients received moclobemide, an reversible monoamine oxidase A inhibitor (RIMA), or a SSRI (fluoxetine, fluvoxamine, paroxetine, sertraline).

RESULTS

Baseline values were similar in all groups. Incidences of impairments of sexual functioning with treatment, whether clinically relevant or not, were 24.3% with moclobemide and 61.5% with SSRIs (physician ratings), with no significant tolerance to these effects. There was a suggestion of differences between the SSRIs in their specific dysfunctions they cause. SSRIs (21.6% of patients) had about ten times the moclobemide rate (1.9%) of sexual dysfunction reported as adverse events. Antidepressant efficacy was comparable between treatments.

CONCLUSION

In patients for whom sexual function is important or sexual dysfunction is present, moclobemide should be considered a first line antidepressant.

Characterization of a novel, antifungal, chitin-binding protein from Streptomyces tendae Tü901 that interferes with growth polarity

The afp1 gene, which encodes the antifungal protein AFP1, was cloned from nikkomycin-producing Streptomyces tendae Tü901, using a nikkomycin-negative mutant as a host and screening transformants for antifungal activity against Paecilomyces variotii in agar diffusion assays. The 384-bp afp1 gene has a low G+C content (63%) and a transcription termination structure with a poly(T) region, unusual attributes for Streptomyces genes. AFP1 was purified from culture filtrate of S. tendae carrying the afp1 gene on the multicopy plasmid pIJ699. The purified protein had a molecular mass of 9,862 Da and lacked a 42-residue N-terminal peptide deduced from the nucleotide sequence. AFP1 was stable at extreme pH values and high temperatures and toward commercial proteinases. AFP1 had limited similarity to cellulose-binding domains of microbial plant cell wall hydrolases and bound to crab shell chitin, chitosan, and cell walls of P. variotii but showed no enzyme activity. The biological activity of AFP1, which represents the first chitin-binding protein from bacteria exhibiting antifungal activity, was directed against specific ascomycetes, and synergistic interaction with the chitin synthetase inhibitor nikkomycin inhibited growth of Aspergillus species. Microscopy studies revealed that fluorescein-labeled AFP1 strongly bound to the surface of germinated conidia and to tips of growing hyphae, causing severe alterations in cell morphogenesis that gave rise to large spherical conidia and/or swollen hyphae and to atypical branching.

Undesirable blood pressure changes under naturalistic treatment with moclobemide, a reversible MAO-A inhibitor--results of the drug utilization observation studies

Blood pressure decrease, associated with postural hypotension, as well as spontaneous hypertension are considered to be typical side-effects of conventional, irreversible and nonselective MAO (A+B) inhibitors. The new generation of reversible MAO-A inhibitors is, however, expected to have negligible cardiovascular effects and low propensity to induce either blood pressure increases or decreases. But, the true incidence of such changes is largely unknown since observation studies, specifically assessing the frequency of blood pressure changes, in unselected population of patients treated in the practice, are lacking.

Assessment of sexual dysfunction in depressed patients and reporting attitudes in routine daily practice: Results of the postmarketing observational studies with moclobemide, a reversible MAO-A inhibitor

OBJECT

The aim of this study was to assess the effect of moclobemide on sexual dysfunction in depressed patients treated under routine conditions in private practice and hospital settings.

METHOD

sexual function was systematically assessed by a specific questionnaire and by recording spontaneously reported adverse events during large prospective postmarketing surveillance studies with moclobemide, carried out in Germany between 1992 and 1995. The data of 4333 patients were collected in two different settings: (a) specialized psychiatric and neurological private practices and (b) psychiatric hospitals.

RESULTS

Up to 70% of depressed patients suffered from Some type of sexual dysfunction at baseline and in about two thirds the dysfunction was rated as moderate to severe. The severity and frequency of sexual dysfunction corresponded well to the severity of depressive syndrome. Sexual functions improved during treatment with moclobemide and the extent of improvement corresponded to the favourable outcome of antidepressant treatment. Deterioration of sexual functions under moclobemide treatment was infrequent and experienced by less than 3% of patients. The frequency of spontaneously reported sexual dysfunction, reported as adverse event, was lower than 0.1%. For a considerable proportion of patients included in the studies sexual function was not systematically recorded: up to 10-20% of data for variables related to sexual function were missing. Unreported sexual functioning varied in dependence of the type of function, age and gender of the patient and treatment settings.

CONCLUSION

The results of the observational studies with moclobemide do not provide evidence that moclobemide induces or intensifies sexual dysfunction in depressed patients under routine daily treatment. The results also demonstrate that the assessment of sexual function in the practice is clearly influenced by the reporting attitudes of patients and physicians.

Direct identification of major histocompatibility complex class I-bound tumor-associated peptide antigens of a renal carcinoma cell line by a novel mass spectrometric method

Melanoma and renal cell carcinoma (RCC) are thought to be the most immunogenic human tumors. Presently a series of tumor-specific peptides of melanoma is being tested in clinical trials with different immunotherapy protocols. In contrast, only one decameric peptide (SPSSNRIRNT) derived from one (ORF2) of three possible open reading frames (ORFs) of a gene named RAGE (Renal tumor AntiGEn) was shown to be the target for tumor-specific CTLs on renal carcinoma cells. One reason for the lack of identification of tumor antigens on RCC compared with melanoma may be the difficulty in generating tumor-specific CTLs as screening instruments. Therefore, our approach was directly to isolate and identify peptides bound to HLA class I molecules of the HLA-A2 and -B8 homozygous RCC line A-498. High performance liquid chromatography-fractionated peptides eluted with acid from immunoaffinity-purified HLA class I-peptide complexes were sequenced and identified for the first time by the novel and highly sensitive mass spectrometric method matrix-assisted laser desorption ionization-post source decay (MALDI-PSD) from minute amounts of 100 fmol to 1.5 pmol of the fractionated peptide samples. Fourteen peptide sequences first deduced from interpretations of the mass spectra were also shown to fulfill other reliability criteria such as matching the mass spectra of the respective synthetic peptides. Some peptides were identified to be derived from genes preferentially activated in malignant tissues or resulted from a possibly mutated gene. The most promising candidate for a CTL epitope is a decameric peptide (PASKKTDPQK) derived from another possible ORF (ORF5) of the RAGE gene and probably presented in association with HLA-B8. This peptide was synthesized and used for the in vitro induction of CTLs that lysed the A-498 cells and another HLA-B8-positive RCC line significantly more strongly than either other RAGE-positive but HLA-B8-negative RCC lines or K562 cells. Sensitive sequencing by MALDI-PSD thus may provide a powerful method of identifying potentially tumor-specific and HLA-restricted antigens, even on native malignant cells and tissues.

Utero-ovarian interaction in the regulation of reproductive function

The physiological regulation of fertile reproductive cycle in mammals depends on interactions between hypothalamus-pituitary, ovarian and uterine stimuli. Over the past 20 years, much has been learned about the interrelation between the affluent and effluent lymph and vascular drainage in and around both ovarian and uterine tissues. An essential feature in the regulation of the fertile cycle is the functional status of the ovary, particularly the corpus luteum. During the time of implantation and the early pregnancy, an active corpus luteum is essential. As human chorionic gonadotrophin (HCG) is important in the maintenance of the corpus luteum, we investigated if it was produced by the cyclic endometrium. Immunohistochemical and in-situ hybridization reactions were performed but neither identified the presence of HCG during the proliferative phase. Positive staining and beta-human chorionic gonadotrophin (beta-HCG) mRNA were observed during the secretory phase in the glandular cells of the endometrium. The results were confirmed by Western blotting of secretory phase endometrium extracts and assessment of the functional secretory capacity of primary endometrial cultures. Polymerase chain reaction (PCR) investigations showed a positive result in the secretory phase. We postulate that, based on the very close morphological interrelation between the uterus and the ovary, the beta-HCG of the endometrium is the primary factor for the maintenance of the corpus luteum and early pregnancy.

Inhibition of dextromethorphan metabolism by moclobemide

This pilot study was conducted to evaluate the potential of the new antidepressant moclobemide to inhibit the cytochrome enzyme P4502D6 (CYP2D6) using the cough suppressant dextromethorphan as a substrate in four extensive metabolizers (EM) of debrisoquine. The subjects received seven oral doses of 20 mg dextromethorphan at 4-h intervals over 2 days (1 and 2) and subsequently moclobemide (300 mg b.i.d.) for 9 days. On days 10 and 11, they received seven doses of 20 mg dextromethorphan in addition to moclobemide. During monotreatment and combined treatment, blood was collected on days 2 and 11, respectively, for determination of dextromethorphan and its demethylated metabolites using automated high-performance liquid chromatography with column switching. Concurrent administration of moclobemide markedly reduced the O-demethylation of dextromethorphan, whereas the N-demethylation of dextrorphan to hydroxymorphinan was not affected. The findings indicate that moclobemide can affect the pharmacokinetics of drugs that are mainly metabolized by CYP2D6.

[Cervical pregnancy: case report and review of the literature]

We report on a 22 years old patient with an intact cervical pregnancy located around the cervical isthmus in the 9th week of gestation. Because of the patients strong desire to maintain the reproductive capability, we performed a transvaginal amniotic sac puncture with local application of methotrexate. Later on we applied a systemic methotrexate therapy because of persistent high serum beta-hCG values. Five weeks later the patients developed heavy vaginal bleeding despite low beta-hCG levels so we are obliged to perform vaginal hysterectomy. Actual aspects about the etiology and diagnosis of this rare disease as well as about different opinions regarding conservative, fertility maintaining therapies are discussed.

[Development of breast surgery including plastic-reconstructive surgery results of the Universitätsfrauenklinik Leipzig]

The previous retrospective analysis surveys the introduction and development of breast surgery between 1992 and 1996 where a total of 741 procedures have been performed at our department. Recently, these operations represent about 10% of all gynecological procedures including small and extended operations. The total of breast surgical procedures have increased fivefold within the early introduction period of two years. Surgery of the breast was performed because of cancer in 335 cases (45%). Breast preserving procedures such as "wide excision" or segment resection with axillary nodal dissection (level I and II) respectively, have advanced from initially 46% in 1993 to 52% at present. 36% of women undergoing modified radical mastectomy receive an immediate breast reconstruction. So far, severe intraoperative complications were not encountered. The rate of postoperative and early complications needing therapy including cases with reoperation for postoperative haematoma formation (0.6%) or cases with impaired wound healing (3.1%) is assessed to be minor.

[Risk assessment in ovarian hyperstimulation syndrome (OHS) using the machine learning system (Decision Master) in 155 in-vitro fertilisations and embryo-transfer (IVF/ET) cycles with a long stimulation protocol]

In 155 selected IVF/ET cycles stimulated with the long protocol 25 cycles with severe OHS are included which turned up later on (purposely overrepresented). An inductive machine learning program is described both in informatics and medical essentials. It is tested whether there exists an algorithm for ruling out the above-mentioned complication in the follicular phase of the same cycle already. By cross validation 89% of the OHS could be predicted and proven by practical rules using hormone and ultrasound values to avoid similar events in ongoing or further cycles.

What happens to patients after the end of a clinical trial? Systematic follow-up observational study of an open moclobemide trial in major depression

Controlled clinical drug trials typically last several weeks. At the end of this fixed time period approximately two-thirds of the patients in trials with antidepressant drugs are classified as responders, i.e. the initial severity score is reduced by about fifty percent. In a clinical perspective this means that many patients, even among the responders, are still quite ill and require further treatment. Nevertheless, to date there do not appear to have been any studies on treatment and course of illness after the termination of controlled clinical trials. In a "naturalistic" follow-up surveillance study of 202 patients who had taken part in a controlled trial with the antidepressant moclobemide for six weeks, treatment and clinical status were monitored through questionnaires sent out to their treating physicians (n = 78) at two assessment points four weeks and six months later. Results showed that sixty percent of patients continued to receive the study drug moclobemide after the completion of the clinical trial. Twenty percent were switched to other antidepressants and twelve percent received no further psychotropic drugs. In the course of six months a considerable variation in treatment modes could be observed. Patients under ongoing active treatment made considerable additional progress. A correlation was found between insufficient response and repeated switching of medication. Patients who had been taken off antidepressant medication because of early good response did not experience early relapse after the end of treatment.

Quality-monitoring of psychotropic drug therapy in post-marketing surveillance. Results of a drug utilization observation (DUO) study on moclobemide

Thanks to their non-intervening nature, post-marketing drug utilization observation (DUO) studies reflect both the properties of the substance under investigation and doctors' treatment decisions, thus-in contrast with clinical trials-allowing the interactions of these two factors to be investigated. A DUO study involving the administration of moclobemide to 9419 patients investigated the prescribing behavior of about two-thirds of all general practitioners and internists in Germany prescribing moclobemide during the study period. The results obtained suggest that, on the whole, moclobemide is being prescribed knowledgeably and correctly for the treatment of the full spectrum of depressive disorders. The management of these patients tended to adhere strictly to existing treatment recommendations while at the same time revealing a certain degree of latitude for treatment optimization. This applies particularly to the utilization of the recommended dosage range, especially in severely depressed states, and the consistent, syndrome-based combination treatment with hypnotics/sedatives or neuroleptics in the respective patient groups indicated. Potential interactions-though comparatively few are known for moclobemide-were taken into account in most cases. The safety profile closely matches the experience gained from clinical trials. Despite the large sample size involved there was no evidence of any hitherto unknown serious events. The experience gained during this survey suggests that the DUO study is a suitable instrument for monitoring the use of an antidepressant in the early post-registration period, enabling action to be taken at an early stage to correct any systematic deviations from the conditions of registration.

Guidelines for the implementation of drug utilization observation (DUO) studies in psychopharmacological therapy. The "Phase IV Research" Task-Force of the Association for Neuropsychopharmacology and Pharmacopsychiatry (AGNP)

The task-force on Phase-IV-Research of the Association for Neuropharmacology and Pharmacopsychiatry (AGNP) has developed guidelines for the implementation of scientifically sound drug utilisation observation studies (DUO studies). These guidelines have been adopted by the executive committee as the position of the association. DUO studies are prospective pharmacoepidemiological studies, by which prescription, illness, and patient data of individual patients are collected without interference with the routine course of treatment. They can answer questions on the interaction of treatment modalities with positive and negative treatment outcome. Scientific standards require that there is a study protocol which describes the epidemiological, statistical, procedural, and quality assurance methodology and states who is responsible for what. As such studies can violate data protection regulations or can be used for sales instead of scientific purposes, consultation of an ethics committee is recommended.

[Immunohistochemical evidence of immuno-reactive hCG in the secretory endometrium in women]

The endometrium is a highly differentiated hormone dependent tissue. Its function is to make an implantation and pregnancy possible. The present study was carried out to investigate whether human endometrial cells are able to produce immune reactivity like hCG (ir-hCG). Immunohistochemical examinations of the endometrium were performed in 15 patients in the proliferative phase, 2 patients in the peri-ovulatory phase and 13 patients in the secretory phase. Immunohistochemical investigations of placenta from women who had an artificial abortion were used as controls. No immunohistochemical reaction in the endometrium could be recognized during the proliferative phase. In contrast a clear reaction was observed in the cells of the epithelium of the endometrium during the secretory phase. At the beginning of the secretory phase the ir-hCG was detected to be in the basal subnuclear region. In the middle of the secretory phase ir-hCG was found in the apical supranuclear region and later on in the glands. In the stroma of the endometrium single immunohistochemical positive cells could be seen. The function of the ir-hCG of the endometrium should be elucidated.

The role of cytochrome P450 2D6 in the metabolism of moclobemide

The metabolic fate of moclobemide (Ro 11-1163), a new reversible and selective inhibitor of monoamine oxidase type A (MAO-A), has been assessed in a pilot study in 2 debrisoquine poor metabolizers (PM) and 4 extensive metabolizers (EM) after multiple oral dosings of moclobemide with and without co-medication of dextromethorphan. Absorption and disposition parameters were not different between PM and EM. Concurrent application of dextromethorphan, a selective substrate of CYP2D6, did not affect the pharmacokinetics of moclobemide. These results indicate that the cytochromal isoenzyme CYP2D6 does not play a major role in the metabolic degradation of moclobemide. Limited CYP2D6 activities because of a genetic defect or co-medications with CYP2D6 substrates should therefore not give rise to elevated moclobemide blood levels.