Efficacy of Lapatinib in Therapy-Resistant HER2-Positive Circulating Tumor Cells in Metastatic Breast Cancer

Background

To evaluate the efficacy of lapatinib, a dual EGFR and HER2 tyrosine kinase inhibitor, in therapy-resistant HER2-positive CTCs in metastatic breast cancer (MBC).

Patients and Methods

Patients with MBC and HER2-positive CTCs despite disease stabilization or response to prior therapy, received lapatinib 1500 mg daily in monthly cycles, till disease progression or CTC increase. CTC monitoring was performed by immunofluorescent microscopy using cytospins of peripheral blood mononuclear cells (PBMCs) double stained for HER2 or EGFR and cytokeratin.

Results

A total of 120 cycles were administered in 22 patients; median age was 62.5 years, 15 (68.2%) patients were post-menopausal and 20 (90.1%) had HER2-negative primary tumors. At the end of the second course, HER2-positive CTC counts decreased in 76.2% of patients; the median number of HER2-positive CTCs/patient also declined significantly (p = 0.013), however the decrease was significant only among patients presenting disease stabilization (p = 0.018) but not among those with disease progression during lapatinib treatment. No objective responses were observed. All CTC-positive patients harbored EGFR-positive CTCs on progression compared to 62.5% at baseline (p = 0.054). The ratio of EGFR-positive CTCs/total CTCs detected in all patients increased from 17.1% at baseline to 37.6% on progression, whereas the mean percentage of HER2-negative CTCs/patient increased from 2.4% to 30.6% (p = 0.03).

Conclusions

The above results indicate that lapatinib is effective in decreasing HER2-positive CTCs in patients with MBC irrespectively of the HER2 status of the primary tumor and imply the feasibility of monitoring the molecular changes on CTCs during treatment with targeted agents.

Trial Registration

Clinical trial.gov NCT00694252     

Iron absorption and distribution in TNFΔARE/+ mice,a model of chronic inflammation

Hemizygous TNF^ΔARE/+ mice are a murine model for chronic inflammation. We utilized these animals to study iron-kinetics and corresponding protein expression in an iron-deficient and iron-adequate setting. ⁵⁹Fe-absorption was determined in ligated duodenal loops in vivo. Whole body distribution of i.v. injected ⁵⁹Fe was analysed, and the organ specific expression of ferroportin, transferrin receptor-1, hepcidin and duodenal DMT-1 was quantified by real-time PCR and Western blotting.Duodenal ⁵⁹Fe-lumen-to-body transport was not affected by the genotype. Duodenal ⁵⁹Fe-retention was increased in TNF^ΔARE/+ mice, suggesting higher ⁵⁹Fe-losses with defoliated enterocytes. Iron-deficiency increased duodenal ⁵⁹Fe-lumen-to-body transport, and higher duodenal ⁵⁹Fe-tissue retention went along with higher duodenal DMT-1, ferroportin, and liver hepcidin expression. TNF^ΔARE/+ mice significantly increase their ⁵⁹Fe-content in inflamed joints and ilea, and correspondingly reduce splenic ⁵⁹Fe-content. Leukocyte infiltrations in the joints suggest a substantial shift of iron-loaded RES cells to inflamed tissues as the underlying mechanism. This finding was paralleled by increased non-haem iron content in joints and reduced haemoglobin and haematocrit concentrations in TNF^ΔARE/+ mice.In conclusion, erythropoiesis in inflamed TNF^ΔARE/+ mice could be iron-limited due to losses with exfoliated iron-loaded enterocytes and/or to increased iron-retention in RES cells that shift from the spleen to inflamed tissues.     

Floristic notes from the mountains of Northern Greece Materials for the Mountain Flora of Greece, 7

The authors present an annotated list of rare or otherwise interesting vascular plants collected in the mountains of northern Greece by themselves in 1979 and by Strid and Georgiadou in 1977. The following are apparently new to Greece: Thesium linophyllon L. ssp. montanum (Ehrh. ex. Hoffm.) Čelak., Moehringia pendulo (Waldst. & Kit.) Fenzl, Gypsophila glomerata Pallas ex. Bieb., Dianthus peiraeus Waldst. & Kit. ssp. noeanus (Boiss.) Tutin, Dianthus superbus L., Ranunculus fon–tanus C. Presl, Thlaspi arvense L., Potentilla apennina Ten. ssp. stoianovii Urum. & Jav., Trifolium badium Schreber, Rhamnus pumila Turra, Viola palustris L., Athamanta albanica Alston & Sandwith, Peucedanum oligophyllum ssp. aequiradium (Vandas) Tutin, Vaccinium gaultherioides Bigelow, Galeopsis speciosa Miller, G. bifida Boenn., Melampyrum sylvaticum L., Odontites lutea (L.) Clairv., Sambucus racemosa L., Symphyandra wanneri (Rochel) Heuffel, Galinsoga parviflora Cav., Achillea distans Waldst. & Kit. ex Willd., Centaurea grbavacensis (Rohlena) Stoj. & Acht., C. indurata Janka, Lactuca aurea (Schultz Bip. ex PanČić) Stebbins, Festuca gigantea (L.) Vill., F. pirinica Horvat ex Markgr.–Dannenb., Sparganium minimum (Hartm.) Fries, and Rhynchospora alba (L.) Vahl.     

Determinants for DNA target structure selectivity of the human LINE-1 retrotransposon endonuclease

The human LINE-1 endonuclease (L1-EN) is the targeting endonuclease encoded by the human LINE-1 (L1) retrotransposon. L1-EN guides the genomic integration of new L1 and Alu elements that presently account for ~28% of the human genome. L1-EN bears considerable technological interest, because its target selectivity may ultimately be engineered to allow the site-specific integration of DNA into defined genomic locations. Based on the crystal structure, we generated L1-EN mutants to analyze and manipulate DNA target site recognition. Crystal structures and their dynamic and functional analysis show entire loop grafts to be feasible, resulting in altered specificity, while individual point mutations do not change the nicking pattern of L1-EN. Structural parameters of the DNA target seem more important for recognition than the nucleotide sequence, and nicking profiles on DNA oligonucleotides in vitro are less well defined than the respective integration site consensus in vivo. This suggests that additional factors other than the DNA nicking specificity of L1-EN contribute to the targeted integration of non-LTR retrotransposons.     

Colloidal stability of carbon nanotubes in an aqueous dispersion of phospholipid

Within the family of nanomaterials, carbon nanotubes (CNTs) have emerged as a new efficient scaffold for studying molecular interactions at interfaces. Poor dispersability of CNTs in any solvent presents a considerable drawback for the development of novel functional composite structures. Previous studies have demonstrated that the solubility of CNTs can be greatly enhanced by employing appropriate surfactants, some of them being biological molecules. In this work, we study the noncovalent wrapping of lipid chains onto the graphitic surface of single-walled material (SWCNTs) by electron microscopy and Raman spectroscopy. Stable and homogenous aqueous suspensions of SWCNTs in the presence of lipids have been prepared, whereas their electrophoretic mobility was confirmed by zeta-potential measurements. Raman measurements revealed that smaller diameter SWCNTs are preferentially dispersed by lipid molecules in the aqueous supernatant part of the prepared suspension.     

Molecular interactions of the mitochondrial Tim12 translocase subunit

The small Tims are chaperones that facilitate insertion of hydrophobic precursors into the inner mitochondrial membrane. We purified Tim12 and found it forms dimers that bind to Tim9. In this interaction, Tim12 undergoes structural changes that may be important for transport of its substrates in the mitochondrial carrier import pathway.     

Interval timing is intact in arrhythmic Cry1/Cry2-deficient mice

Localizing the self in time is fundamental for daily life functioning and is lacking in severe disabling neuropsychiatric disorders like schizophrenia. Brains keep track of time across an impressive range of scales. Great progress has been made in identifying the molecular machinery of the circadian clock, the brain's master clock that operates on the 24-hour scale and allows animals to know the "time of the day" that important events occur, without referring to external cues. However, the biology of interval timing, the mechanism responsible for durations in the seconds-to-minutes-to-hours range, remains a mystery, and an obvious question is whether there is a common biological solution for keeping track of time across these 2 time scales. To address this, we trained Cry1/Cry2 double knockout mice on an interval timing task with durations that ranged between 3 and 27 seconds. The mice were kept under constant light conditions to avoid any exogenously induced form of daily rhythmicity. We observed that the homozygous knockouts displayed as accurate and precise a temporal memory as the control mice. This suggests that the Cry1 and Cry2 genes are not an important component of the interval timer. Furthermore, proper calibration of the interval timer does not depend on a functional circadian clock. Thus, these 2 timing systems likely rely on different and independent biological mechanisms.     

Selective non zinc binding inhibitors of MMP13

Directed screening has identified a novel series of MMP13 inhibitors that possess good levels of activity whilst possessing excellent selectivity over related MMPs. The binding mode of the series has been solved by co-crystallisation and demonstrates an interesting mode of inhibition without interaction with the catalytic zinc atom.     

From research to implementation: Nature conservation in the Eastern Rhodopes mountains (Greece and Bulgaria), European Green Belt

Nature conservation should ideally build on the scientific recommendations that are concluded from applied conservation research, as well as on monitoring schemes that evaluate the effectiveness of recommendations. We considered as a case study a system of six protected areas located in the Eastern Rhodopes mountains in the southern part of the European Green Belt (EGB). To investigate nature conservation effectiveness, we reviewed 196 articles from scientific journals and books, eight doctoral and master theses, and 39 scientific reports regarding the Greek (one protected area, 428 km²) and the Bulgarian (five protected areas, 904 km²) part of the study area. We extracted 743 conservation recommendations, and through questionnaires completed by 10 local experts, we found that 74% of the recommendations were familiar for the experts. In the Greek (GR) and the Bulgarian part (BG) only 52% and 16%, respectively, of the recommendations were implemented, and only 15% (GR) and 3.1% (BG) were implemented and evaluated regarding their effectiveness. According to the experts, the main reasons for non-implementation and non-evaluation were absence or incompetence of the responsible authorities. Some recommendations obtained a remarkable low rate of implementation, such as those regarding agriculture and livestock rearing practices (GR: 29%, BG: 16%) or mammal conservation (GR: 0%, BG: 16%). Some other recommendations obtained rather high rates at least for Greece, such as tourism and environmental education (GR: 57%, BG: 42%) and bird conservation (GR: 57%, BG: 11%). We found that researchers and conservation managers at both sides of the Greek-Bulgarian border face similar implementation problems, related often to the lack of political will for nature conservation and establishment of competent authorities. The role of the EGB is crucial in enhancing the established cross-border collaborations between stakeholders involved in nature conservation.