Interspecific introgression and changes in population structure in a flatfish species complex after the Prestige accident

Oil spills cause aggressive impacts on marine ecosystems affecting immense areas and the species inhabiting them. If wastes are not cleaned up properly, the remnants may affect local populations for a long time. This work focuses on the long-term impacts of the Prestige spillage that occurred off Galician coast (Spain) in November 2002. Model species were two sympatric flatfish, the megrims Lepidorhombus whiffiagonis and Lepidorhombus boscii. Samples obtained before and nine years after the Prestige accident from affected and unaffected areas were genotyped for six hypervariable nuclear markers and for the mitochondrial D-loop sequence. The results revealed a high proportion of post-F1 interspecific hybrids in the area affected, and also increased intraspecific population differentiation likely due to such localized introgression of foreign genes. These changes suggest the appearance of a hybrid zone following the accident and emphasize the need of paying special attention to potential evolutionary impacts of oil spills.

Search for photon-linelike signatures from dark matter annihilations with H.E.S.S

Gamma-ray line signatures can be expected in the very-high-energy (E(γ)>100 GeV) domain due to self-annihilation or decay of dark matter (DM) particles in space. Such a signal would be readily distinguishable from astrophysical γ-ray sources that in most cases produce continuous spectra that span over several orders of magnitude in energy. Using data collected with the H.E.S.S. γ-ray instrument, upper limits on linelike emission are obtained in the energy range between ∼ 500 GeV and ∼ 25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies. No statistically significant signal could be found. For monochromatic γ-ray line emission, flux limits of (2 × 10(-7) -2 × 10(-5)) m(-2) s(-1) sr(-1) and (1 × 10(-8) -2 × 10(-6)) m(-2) s(-1)sr(-1) are obtained for the central part of the Milky Way halo and extragalactic observations, respectively. For a DM particle mass of 1 TeV, limits on the velocity-averaged DM annihilation cross section ⟨σv⟩(χχ → γγ) reach ∼ 10(-27) cm(3)s(-1), based on the Einasto parametrization of the Galactic DM halo density profile.

Abstract P1-07-19: Mass Spectrometry Based Quantitative Analysis of the HER Family receptors in FFPE Breast Cancer Tissue

The human EGF receptor family (HER's) consists of two clinically validated drug targets (EGFR and HER2), a third (HER3) currently under investigation for its possible role in the acquisition of multidrug resistance and a fourth (HER4), the role of which is still matter of debate. Drugs inhibiting EGFR or HER2 show significant antitumor activity in the clinic, however, acquisition of resistance is a hallmark of these and most targeted therapies. In the case of EGFR and HER2, one of the emerging resistance mechanisms is the co-expression of HER3. Indeed, recent reports show that inhibition of the PI3K pathway leads to upregulation of HER3, and subsequent resistance. Clinical analysis of protein levels in formalin fixed paraffin embedded (FFPE) tissues is limited to immunohistochemistry (IHC), which is semi-quantitative and requires significant amounts of tissue. Moreover, the vast majority of research groups consider specific HER3 staining by IHC particularly challenging. However, accurate measurement of these targets is critical both for properly defining treatment groups and predicting patterns of resistance.

In order to address these issues, we used trypsin digestion mapping and stable isotope labeled peptides to develop a panel of quantitative mass spectrometric (MS) assays to measure the levels of EGFR, HER2, HER3 and other clinically relevant targets in FFPE breast cancer tissue. These quantitative MS assays were then multiplexed to analyze 1μg of tumor protein.

In this study, we multiplexed HER family analysis on 31 HER2 positive breast cancers. Tumor tissue was microdissected from FFPE sections, and subjected to quantitative MS analysis of EGFR, HER2, HER3 as well as IGF1R and cMET. Quantitation of HER2 showed a broad range of HER2 expression in these tissues. The highest expresser measured 26 fmol/ug tumor tissue, representing amplification and massive protein over expression. In contrast, five tissues showed low levels of HER2 expression, below 1 fmol/ug, similar to HER2 non-amplified cell lines. This suggests that MS quantitation can identify patients with low expression of HER2 who are unlikely to respond to trastuzumab therapy. As a matter of fact, 3 of these 5 low expressing patients had outcome data and showed no response to trastuzumab treatment.

In 28 of 31 patient tissue samples, HER3 showed low levels of expression (100–300 amol/ug tumor tissue) similar to HER3 expression in cell lines, and comparable to low expressing EGFR and HER2 cell lines. The remaining 3 patients had no detectable HER3. This study demonstrates the feasibility of measuring HER3 in multiplex in FFPE breast cancer tissue. Based on the low but widespread expression of HER3 in this cohort, it may be most useful to assess HER3 expression after initial treatment as a marker of potential resistance to targeted therapies.

Taken together, these data demonstrate that a sensitive and quantitative assay to measure oncoproteins in FFPE clinical samples may help stratify patients with variable expression of these targets. Our quantitation of oncogene expression from clinical samples uses a small amount of tissue, is clinically applicable and alleviates the problem of scoring either positive or negative for the expression of a given protein.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-07-19.

Transport and pharmacodynamics of albitiazolium, an antimalarial drug candidate

BACKGROUND AND PURPOSE

Choline analogues, a new type of antimalarials, exert potent in vitro and in vivo antimalarial activity. This has given rise to albitiazolium, which is currently in phase II clinical trials to cure severe malaria. Here we dissected its mechanism of action step by step from choline entry into the infected erythrocyte to its effect on phosphatidylcholine (PC) biosynthesis.

EXPERIMENTAL APPROACH

We biochemically unravelled the transport and enzymatic steps that mediate de novo synthesis of PC and elucidated how albitiazolium enters the intracellular parasites and affects the PC biosynthesis.

KEY RESULTS

Choline entry into Plasmodium falciparum-infected erythrocytes is achieved both by the remnant erythrocyte choline carrier and by parasite-induced new permeability pathways (NPP), while parasite entry involves a poly-specific cation transporter. Albitiazolium specifically prevented choline incorporation into its end-product PC, and its antimalarial activity was strongly antagonized by choline. Albitiazolium entered the infected erythrocyte mainly via a furosemide-sensitive NPP and was transported into the parasite by a poly-specific cation carrier. Albitiazolium competitively inhibited choline entry via the parasite-derived cation transporter and also, at a much higher concentration, affected each of the three enzymes conducting de novo synthesis of PC.

CONCLUSIONS AND IMPLICATIONS

Inhibition of choline entry into the parasite appears to be the primary mechanism by which albitiazolium exerts its potent antimalarial effect. However, the pharmacological response to albitiazolium involves molecular interactions with different steps of the de novo PC biosynthesis pathway, which would help to delay the development of resistance to this drug.

The effects of weekly augmentation therapy in patients with PiZZ α1-antitrypsin deficiency

Background

The major concept behind augmentation therapy with human α₁-antitrypsin (AAT) is to raise the levels of AAT in patients with protease inhibitor phenotype ZZ (Glu342Lys)-inherited AAT deficiency and to protect lung tissues from proteolysis and progression of emphysema.

Objective

To evaluate the short-term effects of augmentation therapy (Prolastin^®) on plasma levels of AAT, C-reactive protein, and chemokines/cytokines.

Materials and methods

Serum and exhaled breath condensate were collected from individuals with protease inhibitor phenotype ZZ AAT deficiency-related emphysema (n = 12) on the first, third, and seventh day after the infusion of intravenous Prolastin. Concentrations of total and polymeric AAT, interleukin-8 (IL-8), monocyte chemotactic protein-1, IL-6, tumor necrosis factor-α, vascular endothelial growth factor, and C-reactive protein were determined. Blood neutrophils and primary epithelial cells were also exposed to Prolastin (1 mg/mL).

Results

There were significant fluctuations in serum (but not in exhaled breath condensate) levels of AAT polymers, IL-8, monocyte chemotactic protein-1, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor within a week of augmentation therapy. In general, augmented individuals had higher AAT and lower serum levels of IL-8 than nonaugmented subjects. Prolastin added for 3 hours to neutrophils from protease inhibitor phenotype ZZ individuals in vitro reduced IL-8 release but showed no effect on cytokine/chemokine release from human bronchial epithelial cells.

Conclusion

Within a week, augmentation with Prolastin induced fluctuations in serum levels of AAT polymers and cytokine/chemokines but specifically lowered IL-8 levels. It remains to be determined whether these effects are related to the Prolastin preparation per se or to the therapeutic efficacy of augmentation with AAT.

Adverse events risk associated with bevacizumab addition to breast cancer chemotherapy: a meta-analysis

BACKGROUND

Bevacizumab is a monoclonal antibody against vascular endothelial growth factor with the ability to increase progression-free survival in metastatic breast cancer (MBC). A systematic review and meta-analysis was conducted to determine the risk of the most clinically relevant adverse outcomes associated with the use of bevacizumab in the treatment of breast cancer.

PATIENTS AND METHODS

We included phase III clinical trials that used bevacizumab alone or in combination with chemotherapy as for MBC or locally recurrent. Statistical analyses were conducted to calculate summary odds ratio (OR) of the eight most relevant adverse outcomes related with bevacizumab.

RESULTS

Five clinical trials were included in the meta-analysis. Summary odds ratios obtained showed a statistically significant bevacizumab-associated increased risk in four of the adverse outcomes studied: proteinuria (OR = 27.68), hypertension (OR = 12.76), left ventricular dysfunction (LVD) (OR = 2.25), and hemorrhagic events (OR = 4.07). No statistically significant differences were found for gastrointestinal (GI) perforation, vascular events, fatal events, or febrile neutropenia.

CONCLUSIONS

Bevacizumab did increase the risk of LVD and hemorrhagic events. The addition of bevacizumab to chemotherapy in patients with metastatic breast cancer was not associated with a significant increase in grade ≥ 3 arterial or venous thromboembolic events, GI perforation, or fatal events.