The transcriptome of the arbuscular mycorrhizal fungus Glomus intraradices (DAOM 197198) reveals functional tradeoffs in an obligate symbiont

• The arbuscular mycorrhizal symbiosis is arguably the most ecologically important eukaryotic symbiosis, yet it is poorly understood at the molecular level. To provide novel insights into the molecular basis of symbiosis-associated traits, we report the first genome-wide analysis of the transcriptome from Glomus intraradices DAOM 197198. • We generated a set of 25,906 nonredundant virtual transcripts (NRVTs) transcribed in germinated spores, extraradical mycelium and symbiotic roots using Sanger and 454 sequencing. NRVTs were used to construct an oligoarray for investigating gene expression. • We identified transcripts coding for the meiotic recombination machinery, as well as meiosis-specific proteins, suggesting that the lack of a known sexual cycle in G. intraradices is not a result of major deletions of genes essential for sexual reproduction and meiosis. Induced expression of genes encoding membrane transporters and small secreted proteins in intraradical mycelium, together with the lack of expression of hydrolytic enzymes acting on plant cell wall polysaccharides, are all features of G. intraradices that are shared with ectomycorrhizal symbionts and obligate biotrophic pathogens. • Our results illuminate the genetic basis of symbiosis-related traits of the most ancient lineage of plant biotrophs, advancing future research on these agriculturally and ecologically important symbionts.

Developing therapeutic microRNAs for cancer

Despite substantial progress in understanding the cancer-signaling network, effective therapies remain scarce due to insufficient disruption of oncogenic pathways, drug resistance and drug-induced toxicity. This complexity of cancer defines an urgent goal for researchers and clinicians to develop novel therapeutic strategies. The discovery of microRNAs (miRNAs) provides new hope for accomplishing this task. Supported by solid evidence for a critical role in cancer and bolstered by a unique mechanism of action, miRNAs are likely to yield a new class of targeted therapeutics. In contrast to current cancer medicines, miRNA-based therapies function by subtle repression of gene expression on a yet large number of oncogenic factors and are, therefore, anticipated to be highly efficacious. After the completion of target validation for several candidates, the development of therapeutic miRNAs is now moving to a new stage that involves pharmacological drug delivery, preclinical toxicology and regulatory guidelines.

Abstract P3-02-12: Effect of Platelet Function Inhibition on Circulating Tumor Cells in Patients with Metastatic Breast Cancer: A Randomized Phase II Trial

Background: Tumor-recruited platelets have been implicated in tumor cell survival in the circulation, and in tumor cell arrest and adhesion at distant metastatic sites. Tumor cells activate platelets through a variety of mechanisms including the generation of thrombin and ADP. Blockade of platelet activation and aggregation can inhibit metastasis in animal models. Clopidogrel (Plavix) inhibits ADP mediated platelet activation through blockade of the P2Y12 receptor. Aspirin blocks thromboxane production and can partially disrupt thrombin and ADP mediated activation of platelets. We hypothesized that disruption of platelet function and aggregation will result in a decrease in circulating tumor cells (CTC) number. We evaluated the impact of platelet inhibitors clopidogrel and aspirin on CTC in women with metastatic breast cancer.

Methods: Eligible patients had a diagnosis of metastatic breast cancer, had no contraindications to receive aspirin or clopidogrel, and were on a planned anti-neoplastic treatment break or were on stable endocrine therapy for at least 2 months. Maintenance zoledronic acid and/or trastuzumab was allowed. Patients were randomized to receive either aspirin and clopidogrel or no treatment. CTC was measured at baseline, 2 weeks, 1 month, and monthly thereafter. CTC determinations were made via the CellSearch® assay from Veridex®. Platelet aggregation in whole blood using VerifyNow® P2Y12 and aspirin cartridges was performed on all samples to monitor drug compliance. The primary endpoint was proportion of patients with detectable CTC at 1 month.

Results: 48 patients were enrolled, 22 and 19 remained on study at 1 month for the no treatment and treatment arms. Patient characteristics: the median age was 56, 58% of patients were ER positive, 35% were Her2 positive, the median number of organs involved with metastasis was 2, and the median time since diagnosis of metastasis was approximately 22 months. Baseline CTC was ≥1 in 65% of patients and was ≥5 in 13% of patients. Proportion of patients with CTC ≥1 at time of study completion was compared between groups using Fisher's Exact Test and showed no difference between groups. Mean CTC was compared using non-parametric testing and was not different at any time point; however, the no treatment group's mean CTC increased more rapidly over time compared to the treatment group. Medication compliance as monitored by platelet function testing was outstanding. Clopidogrel and aspirin were well tolerated with no patients developing an SAE related to bleeding. Discussion: There was no statistically significant difference between patients who received anti-platelet therapy and those who did not with respect to the primary endpoint, proportion of detectable CTC at one month. In this population of patients with treated metastatic breast cancer, the CTC numbers were lower than expected, which likely decreased our ability to detect a difference in CTC number with anti-platelet therapy. Aspirin and clopidogrel were well tolerated in patients with metastatic breast cancer. Future studies addressing the utility of CTC in clinical settings as well as the potential role for anti-platelet therapy in breast cancer are needed.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-02-12.

Long-term safety and efficacy of oral phentolamine mesylate (Vasomax) in men with mild to moderate erectile dysfunction

The objectives of this study were to evaluate long-term safety and efficacy of phentolamine mesylate, an orally active, rapid-acting alpha-adrenergic receptor antagonist, for the treatment of men suffering from erectile dysfunction (ED). It was an open-label study involving more than 2000 patients. Men received phentolamine mesylate 40 mg or 80 mg (10 tablets/month) as needed for up to 13 months and self-assessed erectile performance using two validated questionnaires. Treatment with phentolamine mesylate was associated with increases in Erectile Function Domain score of the IIEF, successful vaginal penetrations, and in overall satisfaction. Most adverse events were mild or moderate in severity and consistent with the known pharmacodynamic properties of phentolamine. In conclusion, phentolamine mesylate is safe and effective in the long-term treatment of men with mild to moderate ED.

Pharmacokinetics of a triphasic oral contraceptive containing desogestrel and ethinyl estradiol

OBJECTIVE

To demonstrate that pharmacokinetic measurements were made at steady state. Subsequently, dose proportionality for desogestrel and ethinyl E2 kinetics were demonstrated.

DESIGN

Open-label, noncomparative study.

SETTING

Healthy volunteers in an academic research environment.

PARTICIPANTS

Twenty white women who were 19 to 32 years old were solicited via an advertisement. Nineteen of the 20 women completed the study.

INTERVENTIONS

Study medication consisted of three cycles of a triphasic oral contraceptive containing desogestrel and ethinyl E2. Blood samples were taken at baseline and during cycle 3 between -48 and 24 hours on days 1, 7, 14, and 21, with additional sampling times on day 21 at 48, 60, and 72 hours.

MAIN OUTCOME MEASURES

Serum concentrations of 3-keto-desogestrel and ethinyl E2.

RESULTS

Evaluation of the trough serum levels indicated that a steady state of 3-keto-desogestrel had been reached. Statistical analysis on the Cmax, area under the curve (AUC), and Css,min indicated dose proportionality for the administered desogestrel. Ethinyl E2 serum levels obtained at the same time points also reflected steady state levels and showed minimal variability. The statistical analysis on Cmax, AUC, Css,min, and Tmax indicated that the pharmacokinetics of ethinyl E2 on days 7, 14, and 21 were not statistically significantly different, indicating dose equivalency.

CONCLUSIONS

Steady state of 3-keto-desogestrel is reached after each of the three phases and the pharmacokinetics are dose proportional. After reaching steady state, the pharmacokinetics of ethinyl E2 remain constant over time.

Phase III clinical trial with a new oral contraceptive containing 150 micrograms desogestrel and 20 micrograms ethinylestradiol

Results are presented of a Phase III international multicentre trial to study the effect of a new low-dose oral contraceptive (OC) containing 20 micrograms ethinylestradiol and 150 micrograms desogestrel (Mercilon) regarding efficacy, cycle control, blood pressure, and acceptability. Altogether 1,684 women from 12 European countries were included in the study. Four pregnancies occurred, 3 of them patient failures, one tablet failure. The overall Pearl Index was 0.20. The frequency of irregular bleeding was comparable to that recorded with other commonly used low-dose OCs. No serious side effects occurred. The incidence of the most frequently reported subjective side effects--headache, nausea and breast tension--was already low after the first cycle of treatment and decreased to below pretreatment levels with continued use. There was a small increase in mean body weight, which was confined essentially to young women. The preparation did not affect the mean systolic or diastolic blood pressure. This new preparation has thus proved to be an effective, safe and well-accepted ultra low-dose oral contraceptive.

A comparative study on the effects of a monophasic pill containing desogestrel plus 20 micrograms ethinylestradiol, a triphasic combination containing levonorgestrel and a monophasic combination containing gestodene on coagulatory factors

The changes in haemostasis during oral contraception are related to the ethinylestradiol dose present in the formulation taken by the patient. An open, randomized longitudinal study was performed to evaluate and compare the effects that low-dose oral contraceptives (OCs) containing different doses of ethinylestradiol exert on the haemostatic system. Eighty-nine healthy women, aged 18-45 years, were randomly assigned to treatment with 3 different OCs: a monophasic pill containing 30 micrograms of ethinylestradiol plus 75 micrograms of gestodene (GSD/30) (30 subjects), a triphasic pill containing levonorgestrel (TRI/LNG) (28 subjects), a monophasic pill containing 20 micrograms ethinylestradiol plus 150 micrograms of desogestrel (DOG/20) (31 subjects). From every woman, blood samples were collected before treatment and at the 3rd and 6th cycle of pill intake. The number of platelets significantly increased (p less than 0.01) during treatment with TRI/LNG. Fibrinogen plasma values were significantly increased (p less than 0.05) only in women treated with the preparation GSD/30. Fibrinopeptide A (FPA) plasma levels significantly increased (p less than 0.01) during treatment with the pills TRI/LNG and GSD/30, but the levels of FPA were unchanged in the group treated with DOG/20. The overall results of this study confirm that the effects of OCs on haemostasis are dependent on the ethinylestradiol dose. Moreover, they suggest that with reduction of the ethinylestradiol component to 20 micrograms, the effects of OCs on haemostasis seem to be virtually eliminated.