Antiarol cinnamate and africanoside, a cinnamoyl triterpene and a hydroperoxy-cardenolide from the stem bark of Antiaris africana

From the methanol extract of the stem bark of the African tree Antiaris africana Engler, two new bioactive metabolites were isolated, namely, the α-amyrin derivative 1β,11α-dihydroxy-3β-cinnamoyl-α-amyrin (antiarol cinnamate, 1) and a cardiac glycoside, 3β-O-(α-L-rhamnopyranosyl)-14β-hydroperoxy-5β-hydroxy-19-oxo-17β-card-20(22)-enolide (africanoside, 2a), together with the known compounds β-amyrin and its acetate, β-sitosterol and its 3-O-β-D-glucopyranoside, friedelin, ursolic and oleanolic acid, 19-norperiplogenin, strophanthidol, strophanthidinic acid, periplogenin (3a), 3-epiperiplogenin, strophanthidin (3b) and 3,3'-dimethoxy-4'-O-β-D-xylopyronosyl-ellagic acid. Their structures were established on the basis of their spectroscopic data and by chemical methods, while 3a was additionally confirmed by X-ray crystal structure analysis. The aglycone moiety possessing a hydroperoxy group was found for the first time in cardenolides. Compounds 1 and 2a showed no activity against bacteria, fungi, and microalgae; however, the crude extract exhibited a high toxicity against Artemia salina and a selective antitumor activity against human tumor cell lines. Africanoside (2a) effected a concentration-dependent inhibition of tumor cell growth with a mean IC(50) value of 5.3 nM.

Xiamycin, a pentacyclic indolosesquiterpene with selective anti-HIV activity from a bacterial mangrove endophyte

A novel pentacyclic indolosesquiterpene, named xiamycin (1), and its methyl ester (2) have been obtained from Streptomyces sp. GT2002/1503, an endophyte from the mangrove plant Bruguiera gymnorrhiza. The structures were established by 1D and 2D NMR, MS, and X-ray crystallography, and the absolute configuration of 1 was elucidated by the modified Mosher method. Compound 1 exhibits selective anti-HIV activity; it specifically blocks R5 but has no effects on X4 tropic HIV-1 infection. In a panel of cytotoxicity assays, compound 2 showed to be more potent (geometric mean IC(50)=10.13 μM) compared to compound 1 (geometric mean IC(50) >30 μM), with antitumor potency being generally less pronounced. Xiamycin represents one of the first examples of indolosesquiterpenes isolated from prokaryotes.

Hygrobafilomycin, a cytotoxic and antifungal macrolide bearing a unique monoalkylmaleic anhydride moiety, from Streptomyces varsoviensis

A new bafilomycin-type macrolide, named hygrobafilomycin (6), was isolated by a bioassay-guided selection and fractionation from a terrestrial actinomycete, Streptomyces varsoviensis, along with three known derivatives, bafilomycin D (3), C1 (4) and C2 (5). The structure of hygrobafilomycin was fully established by MS and NMR analyses, revealing a hygrolidin-bafilomycin hybrid with an unusual monoalkylmaleic anhydride moiety. Hygrobafilomycin (6) shows strong antifungal, antiproliferative and cytotoxic activities. In a panel of 40 tumor cell lines, compound 6 shows high cytotoxic potency (mean IC(50)=5.3 n).

The use of automatic speech recognition showing the influence of nasality on speech intelligibility

Altered nasality influences speech intelligibility. Automatic speech recognition (ASR) has proved suitable for quantifying speech intelligibility in patients with different degrees of nasal emissions. We investigated the influence of hyponasality on the results of speech recognition before and after nasal surgery using ASR. Speech recordings, nasal peak inspiratory flow and self-perception measurements were carried out in 20 German-speaking patients (8 women, 12 men; aged 38 ± 22 years) who underwent surgery for various nasal and sinus pathologies. The degree of speech intelligibility was quantified as the percentage of correctly recognized words of a standardized word chain by ASR (word recognition rate; WR). WR was measured 1 day before (t1), 1 day after with nasal packings (t2), and 3 months after (t3) surgery; nasal peak flow on t1 and t3. WR was calculated with program for the automatic evaluation of all kinds of speech disorders (PEAKS). WR as a parameter of speech intelligibility was significantly decreased immediately after surgery (t1 vs. t2 p < 0.01) but increased 3 months after surgery (t2 vs. t3 p < 0.01). WR showed no association with age or gender. There was no significant difference between WR at t1 and t3, despite a post-operative increase in nasal peak inspiratory flow measurements. The results show that ASR is capable of quantifying the influence of hyponasality on speech; nasal obstruction leads to significantly reduced WR and nasal peak flow cannot replace evaluation of nasality.

Abstract 2598: Evaluation of antitumor efficacy of Trabectedin in patient derived tumor xenografts in vitro and in vivo, and determination of a predictive gene signature

Trabectedin is a marine derived antitumoral agent, originally isolated from Ecteinascidia turbinata. It acts by binding to the minor groove of DNA interfering with cell division, transcription, and the DNA repair machinery. Trabectedin was approved by the EMEA as second line therapy for the treatment of advanced soft tissue sarcoma and for ovarian cancer in combination with Doxil. Further Phase II trials with Trabectedin in breast and prostate cancer are underway.

We characterized Trabectedin for antitumor efficacy and selectivity in patient-derived tumor xenografts to identify target tumor types for further clinical studies. The compound was tested in 67 tumor xenografts of 15 histo types using an ex vivo clonogenic assay. Pronounced concentration dependent antitumor activity (mean IC70 = 1.3 nM) and selectivity was observed, with sensitive tumor models being on average about 7-fold more sensitive than the average of all tumors tested. Trabectedin was also given to tumor-bearing nude mice at 0.2 and 0.15 mg/kg/d iv once weekly for 3 weeks and showed substantial inhibition of tumor growth at a dose level of 0.2 mg/kg/d in tumors of lung, colon, and breast.

The activity data of Trabectedin against 67 tumors in the clonogenic assay were used for further bioinformatic analysis. Subsets of tumors and their corresponding data were randomly split into a training set (n=44) and an independent validation set (n=23). By matching in vitro antitumor efficacy data (IC70) of the tumors with the corresponding gene expression profiles (determined by Affymetrix HG-U133 Plus 2.0 gene chip array), a signature of 19 gene transcripts being specific for the responsiveness towards Trabectedin was determined. The classification border for activity of Trabectedin was IC70 = 0.5 nM. The signature was validated by leave-one-out-cross-validation (LOOCV) on the training set, and prediction of tumors of the independent validation set. In the LOOCV sensitivity or resistance of tumors was predicted correctly in 13/18 (72%) and 26/26 tumors (100%), in the validation set in 4/7 (57%) and 13/16 tumors (81%), respectively. In the validation set, the predicted responders showed a 4.5-fold lower median IC70 compared to the predicted non-responders (p= 0.02). Moreover, the signature was used to predict responsiveness of 173 tumors of the Oncotest xenograft collection with unknown sensitivity to Trabectedin. In this set of tumors, the signature identified sarcoma, leukemia/lymphoma, as well as ovarian, head and neck, small cell lung, mammary and bladder cancer as Trabectedin sensitive tumor types. Experimental testing of the predicted tumors so far confirmed the predictions in 11/13 cases (85%).

This study shows the feasibility of combining experimental testing and virtual prediction to identify additional tumor types as candidates for further preclinical and clinical investigations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2598.

Abstract 4168: Comprehensive characterisation of a newly established patient-derived pancreatic adenocarcinoma xenograft collection

There is a high medical need to identify new treatments for patients with pancreatic cancer, since in many cases only palliative treatment is possible. The standard 1st line chemotherapy in inoperable, locally advanced (stage II and III) and metastatic (stage IV) adenocarcinoma of the pancreas is Gemcitabine as a single agent with a median survival of about 6 month. In addition, Gemcitabine is indicated as adjuvant chemotherapy after surgery. Although the anti-metabolite 5-Flourouracil (5-FU) and the EGF-R inhibitor Tarceva (Erlotinib) have been approved for 2nd line treatment, new and more efficient drugs are urgently needed. In the present study, more than 60 samples of pancreatic carcinomas were transplanted subcutaneously (s.c.) into NMRI nude mice directly after tumor resection. In most cases, tumor material from chemonaive patients with defined histology and staging was used for implantation. Up to now, 17 tumor models were passaged in nude mice and characterized comprehensively. In general, the histology of the primary tumor was comparable to that of the established xenograft. Chemosensitivity in vivo was evaluated by treatment of tumor bearing nude mice with 5-FU (100 or 75mg/kg, q7dx3, i.p.), Gemcitabine (240mg/kg, q7dx3, i.v.) and Erlotinib (25 and 50mg/kg, qdx21, p.o.). In general, tumor growth was not inhibited with best T/C values &gt;50% highlighting the general chemoresistance of pancreatic cancer. Only for two models (PAXF 1872 and PAXF 1998), a high sensitivity towards Gemcitabine was evident with best T/C values of 8% and 3.8%, respectively. There was no correlation to the transcriptional levels of proteins involved in transportation and metabolism of Gemcitabine. Concerning Erlotinib, best T/C values were ranging from 89.6% (PAXF 1876) to 38.5% (PAXF 1982) with no correlation to EGFR expression status. A more broad chemosensitivity profile was established with the ex-vivo clonogenic assay. Interestingly, several tumors responded strongly to treatment with Rapamycin (IC50 ≤ 10nM). Based on this data, in vivo treatment experiments with RAD001 (Everolimus) were done and data are presented. Mutational analysis of p53 (exons 4 to 10) revealed only 4 out of 13 models as p53 wild-type. Nevertheless, the p53 pathway is dysregulated in all tumor models and for selected tumors, an aneuploid cell population was identified by ex vivo cell cycle analysis.

In summary, a unique collection of patient-derived pancreatic xenograft models of high clinical relevance has been established. These models are available for translational research studies including in-vivo efficacy testing of new investigational drugs.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4168.

[Double gall blader--surprise during operation]

Gall blader abnormalities are very rare. The diagnosis is difficult, more often appears during operation or necropsy. The authors present a clinical case with double gall blader, into a 50 years old man. The diagnosis appeared during laparoscopic cholecystectomy. The colecistectomy was performed for chronic cholelithiasis. Even it is rare, this pathology should be known, to avoid biliary ducts iatrogenic injuries during operations. The authors made a mustering of literature.

Psychometric properties of an index of three patient reported outcome (PRO) measures, termed the CLinical ARthritis Activity (PRO-CLARA) in patients with rheumatoid arthritis. The NEW INDICES study

OBJECTIVES

To evaluate the psychometric properties of an index based on 3 patient reported outcomes measures, termed PRO-CLinical ARthritis Activity (PRO-CLARA), in order to facilitate rapid and easy rheumatoid arthritis (RA) activity assessment in daily routine.

METHODS

196 patients partially or not responding to disease modifying anti-rheumatic drugs (DMARDs), consented to participate in a multicentre cross-sectional study. For the evaluation of the psychometric properties of the PRO-CLARA, this population has been compared to another cohort of 247 outpatients with RA who were participating in a long-term observational study and who satisfying minimal disease activity and remission definitions. All patients completed the PRO-CLARA, combining patient's physical function, self-administered tender joint count and perception of global health status into a single measure of disease activity. Additional comparator composite indices were analysed. Internal consistency was assessed with Cronbach's alpha coefficient. A confirmatory factor analysis was carried out to test factor structure. Concurrent validity was analyzed using Spearman's correlations and cross-tabulations. Discriminant validity to distinguish patients with active and non-active disease was assessed with receiver operating characteristic (ROC) curve analysis. For agreement analysis, kappa statistics were calculated.

RESULTS

In testing for internal consistency, we found that Cronbach's alpha for the PRO-CLARA was 0.893, indicating high reliability. PRO-CLARA proved to be significantly correlated to established RA activity assessment tools. The area under ROC curve of the PRO-CLARA gives identical results to those provided by other comparator indices.

CONCLUSIONS

The study showed satisfactory psychometric properties of the PRO-CLARA.

Impact of calcifications on patient-specific wall stress analysis of abdominal aortic aneurysms

As a degenerative and inflammatory desease of elderly patients, about 80% of abdominal aortic aneurysms (AAA) show considerable wall calcification. Effect of calcifications on computational wall stress analyses of AAAs has been rarely treated in literature so far. Calcifications are heterogeneously distributed, non-fibrous, stiff plaques which are most commonly found near the luminal surface in between the intima and the media layer of the vessel wall. In this study, we therefore investigate the influence of calcifications as separate AAA constituents on finite element simulation results. Thus, three AAAs are reconstructed with regard to intraluminal thrombus (ILT), calcifications and vessel wall. Each patient-specific AAA is simulated twice, once including all three AAA constituents and once neglecting calcifications as it is still common in literature. Parameters for constitutive modeling of calcifications are thereby taken from experiments performed by the authors, showing that calcifications exhibit an almost linear stress-strain behavior with a Young's modulus E ≥ 40 MPa. Simulation results show that calcifications exhibit significant load-bearing effects and reduce stress in adjacent vessel wall. Average stress within the vessel wall is reduced by 9.7 to 59.2%. For two out of three AAAs, peak wall stress decreases when taking calcifications into consideration (8.9 and 28.9%). For one AAA, simulated peak wall stress increases by 5.5% due to stress peaks near calcification borders. However, such stress singularities due to sudden stiffness jumps are physiologically doubtful. It can further be observed that large calcifications are mostly situated in concavely shaped regions of the AAA wall. We deduce that AAA shape is influenced by existent calcifications, thus crucial errors occur if they are neglected in computational wall stress analyses. A general increase in rupture risk for calcified AAAs is doubted.

Fatal outcome of a hepatitis B virus transfusion-transmitted infection

BACKGROUND AND OBJECTIVES

In 2008, hepatitis B virus (HBV) DNA testing was not yet mandatory for the screening of blood donations in Switzerland. At that time, HBsAg was the only specific mandatory marker for HBV. The importance of high sensitivity for HBV NAT screening is shown.

MATERIALS AND METHODS

Donor and recipient of a transfusion-transmitted HBV infection were followed up. Multiple samples were tested for HBV serological and molecular markers.

RESULTS

At donation, the donor appeared healthy, HBsAg was negative and had a normal ALAT level. Ten weeks later, clinical symptoms suggested acute HBV infection as was confirmed with positive HBsAg, HBeAg, anti-HBc IgG, anti-HBc IgM and anti-HBe. The archived sample from the original donation was negative for anti-HBc, but positive for HBV DNA (17 IU/ml). A recipient transfused with the red cell concentrate was HBV DNA positive (3100 IU/ml) 3 months post-transfusion. After five months, HBsAg, HBeAg, anti-HBc and HBV DNA (1.1 x 10(11) IU/ml) were positive. Two weeks later, the patient died from complications associated with HBV infection and his underlying bone marrow disease.

CONCLUSIONS

The present case illustrates the importance of introducing highly sensitive HBV NAT screening strategy to prevent possible HBV transfusion-transmitted infections from donors with low viral load.

Epoxyphomalin A and B, prenylated polyketides with potent cytotoxicity from the marine-derived fungus Phoma sp

Chemical investigation of a strain of the marine-derived fungus Phoma sp. has led to the discovery of epoxyphomalin A (1) and B (2), two new prenylated polyketides with unusual structural features. Epoxyphomalin A (1) showed superior cytotoxicity at nanomolar concentrations toward 12 of a panel of 36 human tumor cell lines. In COMPARE analyses, the observed cytotoxic selectivity pattern of 1 did not correlate with those of reference anticancer agents with known mechanisms of action.

Abstract A173: Profiling of targeted anticancer agents in a panel of 48 patient-derived xenografts using a clonogenic assay

Novel experimental and approved cancer therapeutics target proteins with key functions in mitosis regulation, cell survival and migration, protein turnover or angiogenesis. These targets include receptor tyrosine (Y) kinases like EGF-R, PDGF-R, VEGF-R, c-KIT and FLT-3, serine-threonine (S/T) specific kinases like B-raf and Aurora A/B (ARK), mitotic kinesins like Eg5 (KSP), the chaperone Hsp90 and traditional targets, namely topoisomerase I / II and ß-tubulin. At Oncotest, a unique profiling screen for anticancer agents using a clonogenic assay using a panel of 48 proprietary solid tumor xenografts is routinely done. The xenograft models in general were established directly from patient tumor material, representing all major tumor histotypes (non-small cell lung cancer / NSCLC, pancreatic, prostate, colon, gastric, breast, ovarian and renal cancer, melanoma and sarcoma) as well as niche tumors (pleuramesothelioma, bladder and head and neck cancer). After an initial profiling screen in the 48 tumor panel, follow-up testing in defined tumor histotypes are of high value for hypothesis generation including selection of a clinical development strategy.

Here, activity profiles for inhibitors targeting EGF-R (Erlotinib), Aurora A/B (VX-680), multiple S/T and Y kinases (Sunitinib, Sorafenib), Eg5 (Ispinesib) and tububiln (Vincristine), Hsp90 (17-DMAG) and topoisomerase I (SN-38, active metabolite of Irinotecan) are discussed. Erlotinib displayed a diverse pattern of activity with a mean IC50 = 20.7µM. Selectivity was studied in an extended panel of NSCLC with tumors showing activated EGF-R being mainly most sensitive. The spectrum-kinase inhibitors Sunitinib and Sorafenib displayed weak selectivity with mean IC50 values of 7.9µM and 11.8µM, respectively. The Hsp90 inhibitor 17-DMAG, the topoisomerase I inhibitor SN-38 and Vincristine were highly potent with mean IC50 values of 28nM, 45nM, and 100nM, respectively. For 17-DMAG and SN-38 as examples, tumor xenograft models selected based on clonogenic assay data responded very well in in vivo efficacy tests. Further evaluation of Vincristine in an extended melanoma panel revealed a strong correlation of sensitivity with a B-raf wild type genotype and resistance with the B-raf V600E mutation. This result was described recently for melanoma patients with B-raf mutations, showing a diminished duration of response to treatment with Dacarbazine, Vincristine, Bleomycin, Lomustine, and human leukocyte interferon.

In conclusion, the Oncotest clonogenic assay by retaining important characteristics of the original patient tumor is of high value for profiling of traditional cytotoxic as well as new targeted cancer agents. By revealing diverse activity and resistance patterns, molecular characterization data including gene mutations and expression are guiding the selection of tumor entities and patients likely to respond to therapy.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A173.

Mansouramycins A-D, cytotoxic isoquinolinequinones from a marine streptomycete

Chemical screening of the ethyl acetate extract from the marine-derived Streptomyces sp. isolate Mei37 resulted in five isoquinolinequinones, four new derivatives, mansouramycin A-D (1, 3-5), and the known 3-methyl-7-(methylamino)-5,8-isoquinolinedione (2). Their structures were elucidated by NMR and MS techniques and by comparison with related compounds. Cytotoxicity profiling of the mansouramycins in a panel of up to 36 tumor cell lines indicated significant cytotoxicity of several derivatives, with pronounced selectivity for non-small cell lung cancer, breast cancer, melanoma, and prostate cancer cells.