[Patient with a Fontan circulation undergoing caesarean section: Anesthesiological management]

Adults suffering from congenital heart diseases (CHD) represent a challenge to anesthesiologists because of the diverse pathologies, complex pathophysiology and special treatment strategies. Due to improved therapeutic options for CHD, patient quality of life and life expectancy is increasing, leaving them as a growing population including pregnant patients with CHD. This article presents the main principles of the pathophysiology and anesthesiological management of pregnant patients living with a Fontan circulation based on a case report, which was complicated by an aortic coarctation and atonic uterine hemorrhage.

Microtubule-associated protein tau correlates with estrogen receptor status but not with in vitro paclitaxel sensitivity in primary breast cancer

BACKGROUND

Factors or signatures predicting response to chemotherapeutic agents are of great interest for breast cancer patient care. There is conflicting data regarding microtubule-associated protein tau as predictive marker of paclitaxel sensitivity. Paclitaxel plays an important role in the adjuvant and metastatic therapy of breast cancer. However, a substantial proportion of patients treated with paclitaxel do not derive benefit from this therapy. Therefore, evaluating potential predictive factors is increasingly important. The authors attempted to validate these findings in vitro utilizing the ATP tumorchemosensitivity assay (ATP-TCA).

MATERIALS AND METHODS

The in vitro drug sensitivity to paclitaxel was evaluated in 48 fresh primary breast cancer specimens using the ATP-TCA. ATP-TCA results were analysed using the area under the curve (AUC) of growth inhibition. These results were correlated with the expression of tau mRNA measured by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Tau was also compared between patients with progesterone receptor (PgR) positive and negative and estrogen receptor (ER) positive and negative breast cancer, respectively.

RESULTS

The correlation of tau with the AUC for paclitaxel was weak, Spearman Rho was -0.267 with a p-value of 0.064. As described before, multiple regression analysis confirmed T-stage (p = 0.01) and PR status (p = 0.01) as independent predictors of paclitaxel chemosensitivity. Using multiple regression analysis and defining tau mRNA expression as dependent variable estrogen receptor status as measured by immunohistochemistry was a highly significant predictor for tau mRNA expression (p < 0.001). Grade (p = 0.002) as well as PgR expression (p < 0.001) were also found to be predictors of tau mRNA expression. CON- CLUSIONS: In the present data set the authors were not able to show that MAP-tau mRNA could predict benefit from the addition of a taxane to adjuvant chemotherapy. They found that ER expression is associated with tau protein expression. Estrogen gene transcription is reported to carry weak predictive significance for endocrine sensitivity, therefore it might be worth pursuing whether, tau mRNA could possibly be a predictor for endocrine therapy response.

Combination of GHRH antagonists and docetaxel shows experimental effectiveness for the treatment of triple-negative breast cancers

In preclinical studies, antagonists of growth hormone-releasing hormone (GHRH) have demonstrated inhibitory effects on the growth of various types of cancers expressing the pituitary type of GHRH receptors (pGHRH-R) and/or its active splice variant 1 (SV1). In this study, we investigated the effectiveness of the treatment of MDA-MB-231 human triple-negative breast cancer (TNBC) with GHRH antagonist JMR-132 alone or in combination with docetaxel. Receptor expression in the MDA-MB-231 human breast cancer cell line was evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Cell viability assays were performed on MDA-MB-231 cells treated with JMR-132, docetaxel or in combination. For studies in vivo, a subcutaneous nude mouse xenograft model was used. JMR-132 was administered s.c. at a dose of 10 µg/day and docetaxel at a dose of 10 mg/kg i.p. given on day 1 and 5. Similar regimens were used for the combination of both substances. At the end of the experiment, an mRNA-based human cancer pathway array including 84 major genes was performed on the tumor tissue of mice treated with JMR-132 to elucidate the mechanism of action of GHRH antagonists in vivo. The in vitro proliferation studies revealed that JMR-132 and docetaxel decreased the cell viability in a dose-dependent manner. The combination of both treatments produced a significantly greater inhibition of cell viability compared to the single agents. Treatment of nude mice bearing MDA-MB-231 xenografts with JMR-132 and docetaxel significantly (p<0.05) inhibited tumor growth by 46 and 50%, respectively. Treatment with the combination of JMR-132 and docetaxel led to an inhibition of tumor volume by 71.6% (p<0.001). Polymerase chain reaction array analysis revealed that JMR-132 interacts with signal transduction pathways involved in proliferation, apoptosis and angiogenesis. Our results suggest that GHRH antagonists in combination with taxanes may enhance the efficacy of treatment for patients with TNBC expressing the SV1 and/or the pGHRH receptor.

Abstract 5476: LHRH receptor targeting as mechanism of anti-tumor activity for cytotoxic conjugates of Disorazol Z with the LHRH receptor agonistic peptide D-Lys6-LHRH

Background

For drug-targeting aimed at the treatment of LHRH receptor overexpressing cancers the LHRH receptor agonistic peptide D-Lys6-LHRH has been conjugated to the novel highly cytotoxic natural compound Disorazol Z. As shown previously by early proof of concept in an ovary cancer xenograft model, differentially linked conjugates possess a high potential regarding the treatment of LHRH-R positive tumors [1]. Here we present further characterization of these conjugates with respect to PK/PD parameter and provide evidence that LHRH receptor targeting significantly contributes to their mechanism of action.

Materials and Methods

LHRH-R competitive binding, calcium release and cytotoxic activity were measured by Tag-Lite technology (Cisbio), and Fluo-4 (Invitrogen) or Resazurin-based detection, respectively. PK parameter were assessed by standard procedures followed by LC-MS/MS analysis. For the xenograft studies, tumor fragments were transplanted subcutaneously in female nude mice and treatment was started at a tumor size of approx. 100 mm3.

Results

Disorazol Z - D-Lys6-LHRH conjugates showed varying cytotoxic activity from single digit nanomolar to higher submicromolar EC50 values but comparable LHRH receptor binding and activation in the low nanomolar EC50 range. Comparison in ovarian and triple negative breast cancer xenograft models revealed potent inhibition of tumor growth for the conjugates, whereas equimolar dosing of Disorazol Z failed to reach statistical significance.

PK analysis showed substantial plasma levels for the conjugates with only minor release of Disorazol Z, pointing to stabilization by conjugation and demonstrating reasonable half-life of the intact conjugates as prerequisite for tumor targeting.

In the same tumor models, competition by previous administration of D-Lys6-LHRH provides evidence for LHRH receptor targeting as mechanism of action. Increased sensitivity of LHRH receptor overexpressing cells towards conjugate cytotoxicity, i.e. leading to about 30 fold decreased EC50 values for the conjugate AEZS-125, further supports the LHRH-R dependency of conjugate efficacy.

Conclusions

The presented LHRH receptor-dependent efficacies of Disorazol Z - D-Lys6-LHRH conjugates in vitro and in mouse xenograft models support the principle of tumor targeting by the LHRH receptor as already employed by the drug candidate AEZS-108, which is currently in phase II clinical studies. Preclinical development of Disorazol Z conjugates will be started in the first half of 2013.

Citation Format: Babette Aicher, Tilmann Schuster, Lars Blumenstein, Antje Schubert, Carsten Gründker, Joerg B. Engel, Olaf Ortmann, Rolf Mueller, Eckhard Guenther, Matthias Gerlach, Michael Teifel. LHRH receptor targeting as mechanism of anti-tumor activity for cytotoxic conjugates of Disorazol Z with the LHRH receptor agonistic peptide D-Lys6-LHRH. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5476. doi:10.1158/1538-7445.AM2013-5476

Downregulation of AKT reverses platinum resistance of human ovarian cancers in vitro

Platinum resistance is the most crucial problem for treatment of ovarian cancer. Increasing evidence points towards AKT overexpression as a mechanistic reason for this clinical condition. The present study evaluates the effect of overexpression and downregulation of AKT on the sensitivity to cisplatin in a platinum-resistant human ovarian cancer cell line and the corresponding platinum-sensitive parental cell line. A2780 and A2780cis ovarian cancer cell lines were stably transfected with an AKT-sense and AKT-antisense plasmid. Successful transfection was evaluated by western blot analysis. Cytotoxic effects of cisplatin were evaluated by metabolic (MTT) and clonogenicity assays as well as by FACS analysis. AKT overexpression (confirmed by western blotting) converted platinum-sensitive A2780 into platinum-resistant cells as shown by MTT assay. Importantly, platinum resistance of A2780cis cells could be reversed by downregulation of AKT, as demonstrated by MTT and clonogenicity assays and FACS analysis. Our data provide strong evidence that cisplatin resistance in ovarian cancer is mediated by AKT overexpression and can be overcome by AKT downregulation, thus, providing a rationale for clinical phase II/III studies combining AKT inhibitors with cisplatin.

Targeted chemotherapy of endometrial, ovarian and breast cancers with cytotoxic analogs of luteinizing hormone-releasing hormone (LHRH)

Receptors luteinizing hormone-releasing hormone (LHRH) are expressed in about 80 % of human endometrial and ovarian cancers and account for more than 50 % of breast cancers including triple negative breast cancers. Apart from the pituitary and reproductive organs, no other organs or hematopoietic stem cells express LHRH (GnRH) receptors. Thus, these receptors can be regarded as an ideal target for a personalized medicine approach in cancer therapy. AEZS-108 (formerly known as AN-152) in which doxorubin is linked to the LHRH agonist [D: -Lys(6)]LHRH, appears to be the most advanced compound in late stage clinical development. Results of phase I and phase II clinical trials in patients with gynecological cancers demonstrated anticancer activity without any cardiotoxicity even in highly pretreated patients. AEZS-108 is therefore being considered for phase II trials in triple negative breast cancers and phase III studies in advanced endometrial cancers positive for LHRH-receptor. EP-100 is a membrane-disrupting peptide targeted to LHRH receptors, which is undergoing early clinical studies in ovarian cancer patients.

Peptidomimetic GnRH antagonist AEZS-115 inhibits the growth of ovarian and endometrial cancer cells

BACKGROUND

AEZS-115 (Aeterna Zentaris GmbH, Frankfurt/M, Germany) is an orally active peptidomimetic antagonist of gonadotropin-releasing hormone (GnRH). In various tumors, an autocrine growth-promoting loop has been described for GnRH. The current study evaluates the antitumor activity and mechanism of action of AEZS-115 in models of ovarian and endometrial cancer.

MATERIALS AND METHODS

Human A2780, Acis2780, OAW-42, Ovcar-3, SKOV-3, Hec1A and Ishikawa cells were analyzed for GnRH receptor expression by reverse transcription polymerase chain reaction (RT-PCR). These cell lines were incubated with AEZS-115 at 1, 10 and 100 μM for 24 h, 48 h, and 72 h and the number of viable cells was determined. Fluorescence activated cell sorting (FACS) cell cycle analyses were performed with increasing concentrations of AEZS-115. Co-treatment experiments of cancer cells with GnRH antagonist cetrorelix and peptidomimetic GnRH antagonist AESZ-115 were carried out.

RESULTS

A2780, Acis2780, OAW-42, Ovcar-3, SKOV-3, Hec1A and Ishikawa cells expressed GnRH receptors as demonstrated by RT-PCR. GnRH antagonist AEZS-115 inhibited growth of all cell lines in a dose- and time-dependent manner. Half maximal inhibitory concentration (IC(50)) values at 48 h of incubation were between 7 and 17.5 μM and for 72 h between 4.5 and 12.5 μM. IC(50) values for ovarian and endometrial cancer cells were rather similar. These results were obtained by tetrazolium salt [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; MTT] assay and confirmed by additional crystal violet staining. Cell cycle FACS analysis revealed that AEZS-115 dose-dependently increased the fraction of apoptotic cells. Co-treatment experiments carried out with AEZS-115 and peptidic GnRH-antagonist cetrorelix suggest that the antitumor effect of AEZS-115 is not mediated by blockade of the GnRH receptor.

CONCLUSION

GnRH antagonist AEZS-115 exhibited substantial antitumor activity in ovarian as well as endometrial cancer cell lines. However, this antitumor effect was not mediated by the tumoral GnRH receptors. To identify the mechanism of action of this compound, further research is warranted. Its in vitro antitumor activity makes AEZS-115 a promising candidate for in vivo studies of ovarian and endometrial cancer.

PI3K inhibitor D-116883 is effective in in vitro models of ovarian cancer

BACKGROUND

D-116883 (Aeterna Zentaris GmbH, Frankfurt, Germany) is an orally effective drug that acts via inhibition of phosphatidylinositol 3-kinase (PI3K). The PI3K/AKT signal transduction pathway is involved in ovarian cancer tumorigenesis. Phosphatase and Tensin homolog (PTEN) loss and other activating mutations frequently contribute to the activation of this pathway. We tested whether D-116883 exerts cytostatic effects in in vitro models of ovarian cancer and analyzed the induced programmed cell death.

MATERIALS AND METHODS

We evaluated the potency of D-116883 in four ovarian carcinoma cell lines with different cellular assays. The effects of D-116883 on cell proliferation was analysed by crystal-violet staining and tetrazolium salt [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; MTT] assay. The capacity for anchorage-independent growth was analyzed in two ovarian carcinoma cell lines without and with D-116883 addition by using the soft agar assay. Fluorescence activated cell sorting (FACS) cell cycle analyses were performed. Cells were incubated with multicaspase inhibitor benzyloxycarbonyl-val-ala-asp(OMe)-fluoromethylketone (zVAD) and inhibitor of necroptosis necrostatin.

RESULTS

Growth inhibition occurred in all ovarian carcinoma cell lines studied (A2780, A2780cis, OAW42 and SKOV3) in a micromolar range (IC(50)<1 μM). By using soft agar assay, a reduced capacity for anchorage-independent growth, a hallmark of tumor cells, caused by D-116883 was demonstrated. Cell cycle analyses showed that D-116883 dose-dependently increased apoptotic cells. Multicaspase inhibitor zVAD and inhibitor of necroptosis necrostatin did not abrogate the growth-inhibiting effect of the compound.

CONCLUSION

PI3K inhibitor D-116883 showed substantial cytotoxic effects in various in vitro models of ovarian cancer. Our results make D-116883 a good candidate for further ovarian cancer research including in vivo experiments.

[Late interruption of pregnancy due to foetal disease: is an inductive method for the generation of ethical principles applicable?]

BACKGROUND

The current study investigates if an inductive method for the generation of ethical principles can be applied to the crucial moral question if late interruption of pregnancy due to fetal disease is ethically adequate.

METHODS

This method originates from the US American philosopher John Rawls and puts a group of so-called competent moral investigators in the beginning of the decision process. These competent moral investigators should be objective, tolerant and sensitive. Thus, real cases which lead to an intuitive, unanimous and clear decision of the competent moral investigators are analysed for the underlying ethical principles. The ethical principles thus detected are then applied to more complicated cases which could not be assessed clearly.

RESULTS

In the current study, the case of foetal trisomy 18 and foetal palate cleft could be clearly judged with a yes and a no, respectively, with regard to an approval of late interruption of pregnancy. The underlying ethical principle leading to these decisions is the utilitaristic principle of minimising harm for mother and fetus.

DISCUSSION

We then tried to apply this principle to a case of foetal trisomy 21, however, no clear decision for an approval or a disapproval of the interruption of pregnancy could be found as it was not possible to assess foetal interests.

P1-01-06: Mechanisms of Tumor Immune Escape in Triplenegative Breast Cancers (TNBC) with and without Mutated BRCA 1

Background

Triplenegative breast cancer (TNBC) is associated with a dismal prognosis, although these tumors are chemosensitive. This phenomenon could be at least in part due to tumor immune escape. The current study investigates the host's immune response to TNBC cells and explores the presence of immunesuppressive factors, such as pAKT-expression and infiltration with FoxP3 positive regulatory T-cells (Tregs), in human TNBC samples.

Material and Methods: NK-cell induced lysis of tumor cells was evaluated in human breast cancer cell lines MCF-7 (ER/PR pos.), HCC 1937 (triplenegative, BRCA 1 mutated) and HCC 1806 (triplenegative). Expression of pAKT and infiltration with Tregs was determined by immunehistochemistry and evaluated semiquantatitavely (0 no expression- 3 strong expression). Control groups consisted of: Fibroadenoma (N=6), prohpyhlactic mastectomy (BRCA 1 mutated, N=3), ER/PR + breast cancer (N=13). They were compared with triplenegative breast cancers: N = 9 BRCA wildtype and N = 6 BRCA 1 mutated.

Results: At an effector target/target-ratio of 10/1 NK-cell induced lysis in HCC 1937 and HCC 1806 was 2.27 and 4.45 increased, respectively, as compared to MCF 7 cells. No infiltration with Tregs was detected in fibroadenoma and prophylactic mastectomy samples. Infiltration with FoxP3-positive Tregs was 0.92 +/− 0.75 in ER/PR+ breast cancers and 2.66 +/−0.5 (p&lt;0.05) in TNBC and 2.16 +/−0.98 (p&lt;0.05) in TNBC with BRCA mutation, respectively. Expression of pAKT was 1.45 +/− 1.29 in ER/PR + breast cancers and 1.77 +/−1.20 in TNBC and 2.66 +/−0.51 (p&lt;0.05) TNBC/with BRCA mutation.

Discussion: TNBC cells stimulated the NK-cell response to a stronger extent than did ER-positive MCF 7 cells mirrored by a more pronounced NK-cell- induced lysis. Thus, the observed stronger infiltration with FoxP3-positive Tregs in TNBC tumor samples could reflect a compensatory mechanism to suppress the host's immune response. In other tumor entities, such as ovarian cancer infiltration with Tregs is associated with a worse overall survival (1). Thus, the significantly increased infiltration with Tregs, could suggest that the worse prognosis of TNBC is due to tumor immune escape and further investigation of immunemodulatory therapeutic strategies in TNBC could prove fruitful.

(1) Specific recruitment of regulatory T cells in ovarian carcinoma fosters immune privilege and predicts reduced survival.

Curiel TJ, Coukos G, Zou L, Alvarez X, Cheng P, Mottram P, Evdemon-Hogan M, Conejo-Garcia JR, Zhang L, Burow M, Zhu Y, Wei S, Kryczek I, Daniel B, Gordon A, Myers L, Lackner A, Disis ML, Knutson KL, Chen L, Zou W.

Nat Med. 2004 Sep;10(9):942–9.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-01-06.

P3-18-06: AEZS-131 – A Highly Selective ERK-Inhibitor: Characterization and Preclinical Testing in Triple Negative Breast Cancer (TNBC)

Introduction: Overexpression of MAPK has been detected in 34 % of TNBC and has been found to be associated with anthracycline resistance (1). AEZS-131 is a highly selective orally active ERK1/2-inhibitor, which has shown in vivo activity (first in class) in colon cancer. The following study explores mode of action and efficacy in models of TNBC.

Study design: AEZS-131 was tested in a kinase panel of 36 STK, 26 TK and 7 PIK to check for selectivity. Inhbition of Rsk-phosphorylation (cellular substrate of ERK) was evaluated by western blot analysis. Mode of action was explored by cell cycle FACS-analysis. Cleavage of PARP was explored by Western blot. Cytotoxic efficacy was evaluated in 5 TNBC, of which 2 had mutations in the MAPK signal transduction pathway lines, by MTT assay. Additionally it was explored if inhibition of classical apoptosis could abrogate the effect of AEZS-131.

Results: AEZS-131 selectively inhibited ERK with an IC50&lt;4nM. Phosphorylation of Rsk-1 the cellular substrate of ERK was inhibited with an IC 50 of 158 nM. AEZS-131 induced cell cycle arrest in G1 dose-dependently and cleavage of PARP. EC 50 was 0,739 μM for MDA-MB-231 (Ras-mutated), 0,137 μM for MDA-MB-435s (B-RAF mutated), 17,5 μM for MDA-MB-468 (PTEN loss), 25 μM for HCC 1806. HCC 1937 were not inhibited by the compound. Of note, inhibition of classical apoptosis did not alter the cytotoxic effect of the compound in MDA-MB-468 and HCC-1806 cells.

Conclusions: AZS-131 was shown to selectively inhibit ERK at low nM concentrations and to induce G1-arrest. Accordingly, the cytotoxic effect most pronounced in TNBC cell lines with mutations in the MAPK pathway. If classical apoptosis is inhibited, cytotoxic effects remain unchanged, suggesting that AEZS-131 can also induce nonclassical forms of programmed cell death. AEZS-131 should be further explored in TNBCs with overexpression of MAPK or mutations in the MAPK-pathway.

*Æterna Zentaris GmbH, Frankfurt/M, Germany.

(1): MAPK overexpression is associated with anthracycline resistance and increased risk for recurrence in patients with triple-negative breast cancer.

Eralp Y, Derin D, Ozluk Y, Yavuz E, Guney N, Saip P, Muslumanoglu M, Igci A, Kücücük S, Dincer M, Aydiner A, Topuz E.

Ann Oncol. 2008 Apr;19(4):669–74.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-18-06.

[Myocardial infarction in the 34th week of gestation: case report]

Acute myocardial infarction during pregnancy is a rare event that is often associated with a very high maternal mortality, estimated to be from 19 to 37%. During the last decades the incidence of myocardial infarction during pregnancy has increased . The main contributing factor could be a higher prevalence of the metabolic syndrome. The strongest predictors correlated with a myocardial infarction are hypertension, diabetes mellitus and advanced maternal age. In addition, improved diagnostic tools could explain the elevated incidence of myocardial infarction during pregnancy. In general gestation is not considered a risk factor for myocardial infarction but gravidity is accompanied by an increase in oestrogen and progesterone levels. It is generally accepted that oral contraceptives increase the risk of coronary heart disease. We present a case where a 37-year-old gravida was admitted to hospital with diffuse thoracic pain. In the patient's history, we found several putative reasons for the thoracic pain that pointed to a musculoskeletal cause. Based on an elevation of ischaemic heart markers and continuous non-specific thoracic pain we performed a primary Cesarean section. In the coronary angiography procedure that followed, a thrombotic occlusion of the ramus diagonalis was diagnosed. We here describe the differential diagnosis as well as the problems associated with diagnosing myocardial infarction in the third trimester of pregnancy.

Pleomorphic adenoma of the breast initially misdiagnosed as metaplastic carcinoma in preoperative stereotactic biopsy: a case report and review of the literature

Pleomorphic adenoma (PA) is a benign mixed tumor found commonly in the salivary glands but rarely in the breast. PA might be misinterpreted clinically and pathologically as a malignant tumor. The differential diagnoses include fibroadenoma, phyllodes tumor and metaplastic carcinoma. Metaplastic carcinoma is the most important entitiy with respect to differential diagnoses, as surgical overtreatment, i.e., mastectomy may be the result. We describe one of the first cases of PA initially misdiagnosed as metaplastic carcinoma (osteoid-chondroid type) in a preoperative stereotactic biopsy and review the literature regarding this entity.

Abstract PD02-05: Low Immunogenicity of Breast Cancer Stem Cells Leads to Selective Survival When Challenged with Trastuzumab and Natural Killer Cells

Although trastuzumab (Herceptin) has substantially improved the overall survival of patients with mammary carcinomas, even initially well-responding tumors often become resistant. Considering that clinical efficacy of trastuzumab correlates with the infiltration of natural killer (NK) cells into the tumor site, we established a cell-culture-system to select for ovarian cancer and mammary carcinoma cells that survive a challenge by trastuzumab and NK cells. Under these conditions, NK cells can eliminate tumor cells either via antibody-dependent-cell-mediatedcytotoxicity (ADCC) or by direct recognition of tumor-associated ligands for NKG2D or DNAM-1. The most striking phenotypic alteration observed in immunoselected ovarian cancer cells was a down-regulation of HER2 expression, leading to an ADCC-resistant phenotype. All breast cancer cells tested (MCF7, SK-BR-3, MDA-MB231, BT474), however, failed to develop resistance in vitro. Instead, treatment with trastuzumab and polyclonal NK-cells resulted in the preferential survival of individual sphere-forming cells that displayed a CD44highCD24low ‘'cancer-stem-celllike” phenotype (CSC) and expressed significantly less HER2 compared with non-stem cells. Moreover, the molecular determinants for the direct recognition of transformed cells, most notably the NKG2D ligands MICA, MICB, ULBP1-4 and the DNAM-1 ligands CD112 and CD155, were virtually absent from CSC.

When immunoseleced breast cancer cells were then re-expanded, they mostly lost the observed phenotype and regenerated a tumor cell culture that displayed initial HER2 surface expression and ADCC susceptibility, but was enriched in CD44highCD24low CSC. This translated into increased clonogenicity in vitro and tumorigenicity in vivo. We provide evidence that recruition of NK-cells and induction of ADCC by trastuzumab may spare actual tumor-initiating-cells, which could explain clinical relapse. Moreover, our observation that “relapsed” in vitro cultures show identical HER2 surface expression and susceptibility toward ADCC suggests that administration of trastuzumab beyond relapse might be considered, especially when combined with proteasome inhibition which increase the expression of NKG2D ligands.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD02-05.

The moral status of the embryo: an attempt at an analysis with the aid of David Hume's ethics

This article applies the moral sentimentalism founded by David Hume to the moral status of the embryo. It will attempt to explain the paradoxical fact that in Germany abortion is common and socially accepted while preimplantation genetic diagnosis is banned with the aid of an approach based on moral sentimentalism. David Hume established the thesis that the human being is guided by the emotions and not by reason when making moral decisions. Scientific innovations often create a feeling of anxiety. Consequently, the initial moral judgment about it is negative. Due to this habit, the innovation is often accepted after a phase of indifference. This phenomenon has been observed in the case of heart transplantation, as well as for IVF. Consequently, the apparent contradiction in the varying degrees of the embryo's worthiness of protection in the womb and in the Petri dish is due to the simple fact that these are different stages of habituation. Therefore, the ethics of Hume cannot stipulate the embryo's moral status for once and for all; however, they can paradoxically raise the ongoing current debate to a more rational level through the insight that the underlying moral concepts are not based on reason alone.

Pregnancy-triggered antiphospholipid syndrome in a patient with multiple late miscarriages

Antiphospholipid syndrome (APS) is a multisystemic disorder of coagulation-causing thrombosis in the arterial and venous system as well as pregnancy-related complications such as miscarriage, stillbirth, preterm delivery and pre-eclampsia. The disease is characterized by the autoimmune production of antibodies against phospholipid, a substance found in the cell membrane. We here report the case of a patient with four second trimester miscarriages, who apart from a heterozygous plasminogen activator-inhibitor-1 mutation, had no risk factors explaining her condition. In the subsequent pregnancy she was therefore put on low-molecular-weight heparin, aspirin and granulocyte colony-stimulating factor. Antiphospholipid antibodies (APL), which had been negative before gestation, increased and remained high throughout pregnancy, thus suggesting a pregnancy-induced or -aggravated APS. The patient was kept on the above-mentioned medication and delivered a healthy male baby by Caesarean section after an otherwise uneventful pregnancy. Thus, in order to diagnose and treat pregnancy-triggered APS in patients with unexplained recurrent miscarriage, screening for APL should also be performed at several time points after conception.

Whole blood-derived miRNA profiles as potential new tools for ovarian cancer screening

BACKGROUND

Screening is an unsolved problem for ovarian cancer (OvCA). As late detection is equivalent to poor prognosis, we analysed whether OvCA patients show diagnostically meaningful microRNA (miRNA) patterns in blood cells.

METHODS

Blood-borne whole miRNome profiles from 24 patients with OvCA and 15 age- and sex-matched healthy controls were biostatistically evaluated.

RESULTS

Student's t-test revealed 147 significantly deregulated miRNAs before and 4 after Benjamini-Hochberg adjustment. Although these included miRNAs already linked to OvCA (e.g., miR-16, miR-155), others had never before been connected to specific diseases. A bioinformatically calculated miRNA profile allowed for discrimination between blood samples of OvCA patients and healthy controls with an accuracy of >76%. When only cancers of the serous subtype were considered and compared with an extended control group (n=39), accuracy, specificity and sensitivity all increased to >85%.

CONCLUSION

Our proof-of-principle study strengthens the hypothesis that neoplastic diseases generate characteristic miRNA fingerprints in blood cells. Still, the obtained OvCA-associated miRNA pattern is not yet sensitive and specific enough to permit the monitoring of disease progression or even preventive screening. Microarray-based miRNA profiling from peripheral blood could thus be combined with other markers to improve the notoriously difficult but important screening for OvCA.

Expression of transketolase-like 1 protein (TKTL1) in human endometrial cancer

BACKGROUND

Malignant tumors metabolize glucose to lactate even in the presence of oxygen (aerobic glycolysis). The metabolic switch from oxidative glycolysis to non-oxidative fermentation of glucose and proteins performed by the tumor cells seems to be associated with TKTL1 and pAkt overexpression. Therefore the aim of the present study was to investigate the expression of TKTL1 and pAkt in human specimens of endometrial cancer as compared to benign endometrium. Additionally, expression of the glucose transporter GLUT1 was also investigated as aerobic glycolysis is associated with an increased need for glucose.

MATERIALS AND METHODS

Levels of TKTL1, pAkt, and GLUT1 expression were immunhistochemically evaluated on paraffin embedded biopsy material from 10 benign and 41 malignant endometrial tissue samples. TKTL1 mRNA levels in the endometrial cancer cell lines Ishikawa and HEC-1A were evaluated by RT-PCR.

RESULTS

Expression of TKTL1, GLUT1 and pAKT was significantly increased in endometrial carcinomas as compared to benign endometrial tissue. There was a significantly weaker TKTL1 expression in highly differentiated G1 tumors. In the human endometrial cancer cell lines Ishikawa and HEC-1A, TKTL1 mRNA was clearly detectable.

CONCLUSION

The levels of TKTL1, GLUT1 and pAKT expression point to the glycolytic phenotype of malignant endometrial tissue. Given the pronounced TKTL1 expression across all different subtypes of endometrial cancer, this protein could serve as a target for future cancer treatments.

Overexpression of polycomb protein BMI-1 in human specimens of breast, ovarian, endometrial and cervical cancer

INTRODUCTION

The polycomb group (PcG) proteins form chromatin-modifying complexes that are commonly deregulated in cancer. The PcG protein BMI-I is overexpressed by various tumours and thus may contribute to malignant transformation. The current study investigated the expression of BMI-I in human specimens of breast, ovarian, endometrial and cervical cancer.

MATERIALS AND METHODS

Expression of BMI-I was evaluated in human ovarian cancer samples by Western blot analysis and immunohistochemistry (IHC) and compared to healthy ovarian tissue. BMI-I expression in human specimens of breast, endometrial and cervical cancer was evaluated by IHC and then compared with the respective benign tissues.

RESULTS

BMI-I was significantly (p<0.05) overexpressed in human breast, ovarian, endometrial and cervical cancer specimens as compared to benign controls. BMI-I expression was also more pronounced in the ovarian cancer samples as demonstrated by Western blot analysis. In human breast cancer samples, BMI-I expression was most pronounced in the invasion front of the tumour.

CONCLUSION

The current study showed for the first time that the BMI-I protein is significantly overexpressed in ovarian, endometrial and cervical cancer and may thus be a potential target for novel antitumor therapies.

Orally active gnRH-antagonist AEZS-115 inhibits growth of human ovarian and breast cancers in vitro

Abstract #3065

Introduction: AEZS-115 is an orally active peptidomimetic antagonist of GnRH, which has been shown to block the pituitary GnRH receptor in nanomolar range. Recently an increasing number of human cancers have been demonstrated to express receptors for GnRH, which mediate growth promoting signals. Accordingly, we tested the antitumor activity of AEZS-115 in in vitro models of human breast and ovarian cancer.&#x2028; Material and Methods: Human ovarian SKOV3, Ovcar 3 as well breast cancer cell line MDA-MB 468 were analyzed for GnRH receptor expression by immunocytochemistry. To screen for a putative anti-tumor effect, these cell lines were incubated with increasing concentrations of AEZS-115, peptidic GnRH-antagonist Cetrorelix and GnRH-agonist Triptorelin (1, 10, 100 µm) for 48 hours and the number of viable cells was determined by crystal violet staining as well as by ATP-dependent luminometric assay.&#x2028; Results: Cell lines SKOV3, OVCAR3 and MDA-MB 468 expressed GnRH I receptors as demonstrated by immunehistochemistry. Both GnRH-antagonists dose dependently inhibited growth of all three cell lines, while GnRH-agonist Triptorelin showed marginal growth inhibition. At 10 µM AEZS-115 inhibited cell growth by 40-60%, at 100 µM growth inhibition was 60-80%. Inhibition with Cetrorelix at 100 µM ranged from 20-40%, while only minor effects on cell growth were seen at 10 µM. These results obtained by crystal violet staining were confirmed by additional luminometric evaluation of the ATP content after treatment with the respective substances.&#x2028; Conclusions: To our knowledge here we report for the first time in vitro anti-cancer activity for a peptidomimetic GnRH antagonist.&#x2028; AEZS-115 showed substantial anti-tumor activity in human ovarian and breast cancer cell lines, while GnRH-agonist Triptorelin showed only minor growth inhibition. Surprisingly AEZS-115 was somewhat more potent than peptidic GnRH-antagonist Cetrorelix. Due to the good antitumor-activity and the possible oral administration AEZS-115 should be a promising candidate for in vivo studies.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3065.

Prolonged clinical benefit from platinum-based chemotherapy in a patient with metastatic triple negative breast cancer

Triple negative breast cancer is a recently defined subgroup of tumors which do not express receptors for estrogen or progesterone and which do not show any overexpression of HER2 receptors. Tumors with these histopathologic features have an unfavorable prognosis and at present there is no standard chemotherapy regimen available. However, experimental studies and very recently some clinical data showed a benefit from platinum-based chemotherapy. We treated a 52-year-old caucasian female with metastatic triple negative breast cancer. She suffered from extensive liver disease resistant to taxane treatment and yttrium radiotherapy. Cisplatin/ifosfamide (12 cycles) induced regression of the liver metastasis from over 30 cm to 6 cm as revealed by CT scan. Dose-limiting toxicity was impairment of renal function and pancytopenia. The patient has now been stable for over ten months on a metronomic regimen of oral cyclophosphamide. This case report adds to recent evidence suggesting good clinical benefits of platinum-based regimens in early and advanced triple negative breast cancers.

Inhibition of estrogen receptor positive and negative breast cancer cell lines with a growth hormone-releasing hormone antagonist

GHRH antagonists have been shown to inhibit growth of various human cancer cell lines xenografted into nude mice including estrogen receptor negative human breast cancers. Previous observations also suggest that GHRH locally produced in diverse neoplasms including breast cancer might directly affect proliferation of tumor cells. In the present study we demonstrate that a novel highly potent GHRH antagonist JMR-132 strongly inhibits the proliferation of both estrogen receptor negative SKBR 3 and estrogen receptor positive ZR 75 human breast cancer cell lines in vitro. The proliferation in vitro of ZR 75 and SKBR 3 was increased after direct stimulation with GHRH(1-29)NH2. The GHRH antagonist JMR-132 had a significant antiproliferative activity in the absence of GHRH and nullified the proliferative effect of GHRH in these cell lines. SKBR 3 and ZR 75 expressed the GHRH ligand as well as the pituitary type of GHRH-receptor, which likely appears to mediate the antiproliferative mechanisms in these cell lines. These in vitro results suggest that JMR-132 is a potent inhibitor of breast cancer growth, independent of the estrogen receptor status. Further investigations on the combination treatment with endocrine agents affecting the estrogen pathway and GRHR antagonists are needed in order to improve the treatment of breast cancer.

The role of regulatory T cells in ovarian cancer

Regulatory T cells (T(reg)), also termed suppressor T cells, control self-reactive T cells in the periphery, thereby conferring protection against immunologic self-destruction. While T(reg) are essential for the prevention of autoimmunity, they also inhibit immune responses against tumor antigens. This is corroborated by an increased mortality rate associated with the presence of a high number of intratumoral T(reg). Tumor infiltration by non-T(reg), on the other hand, is predictive for a substantially longer patient survival. These clinical data suggest that ovarian cancer patients can spontaneously mount effective antitumor immune responses that are undermined by T(reg)-mediated tolerization. The present article reviews clinical and experimental findings on T(reg) in ovarian cancer, with special regard to potential therapeutic implications, which may result from the existing evidence.