Andrzej Błauż

Half-Sandwich Ruthenium(II) Biotin Conjugates as Biological Vectors to Cancer Cells

Ruthenium(II)-arene complexes with biotin-containing ligands were prepared so that a novel drug delivery system based on tumor-specific vitamin-receptor mediated endocytosis could be developed. The complexes were characterized by spectroscopic methods and their in vitro anticancer activity in cancer cell lines with various levels of major biotin receptor (COLO205, HCT116 and SW620 cells) was tested in comparison with the ligands. In all cases, coordination of ruthenium resulted in significantly enhanced cytotoxicity. The affinity of Ru(II) -biotin complexes to avidin was investigated and was lower than that of unmodified biotin. Hill coefficients in the range 2.012-2.851 suggest strong positive cooperation between the complexes and avidin. To estimate the likelihood of binding to the biotin receptor/transporter, docking studies with avidin and streptavidin were conducted. These explain, to some extent, the in vitro anticancer activity results and support the conclusion that these novel half-sandwich ruthenium(II)-biotin conjugates may act as biological vectors to cancer cells, although no clear relationship between the cellular Ru content, the cytotoxicity, and the presence of the biotin moiety was observed.

Synthesis and biological activities of ferrocenyl derivatives of paclitaxel

A series of ferrocenyl taxoids were prepared by acylation of paclitaxel and docetaxel with ferrocenecarboxylic acid and 3-ferrocenoylpropionic acid in good yield. The prepared compounds showed high activities against multidrug-resistant colon adenocarcinoma cell lines.

Interaction between antioxidants in assays of total antioxidant capacity.

Sub-additivity of antioxidant activities in assays of total antioxidant capacity has been reported previously and ascribed to binding of low-molecular weight antioxidants such as flavonoids by proteins. We demonstrate that this phenomenon is much more common and concerns also interactions between typical low-molecular weight oxidants in the assays of ABTS- decolorization and protection of fluorescein from AAPH-induced bleaching. The subadditive interactions between antioxidants may affect quantitative considerations drawn from in vitro assays of antioxidant capacity of biological samples.

Montelukast treatment may alter the early efficacy of immunotherapy in children with asthma

BACKGROUND Allergen-specific immunotherapy (SIT) is the only available potentially curative approach in the management of allergic diseases. Therapies that boost regulatory T cell induction during SIT might further enhance its effectiveness. OBJECTIVE The purpose of this study was to assess the effect of montelukast treatment on early clinical and immunologic effects of allergen-specific immunotherapy in children with asthma. METHODS It was a randomized, double-blind, placebo-controlled trial conducted in 36 children with asthma and allergy to house dust mites who required from 400 to 800 microg of inhaled budesonide per day during the 7-month run-in period. Patients were randomly allocated to receive 5 mg montelukast daily (n = 18) or placebo (n = 18) as an addition to inhaled corticosteroid (ICS) treatment during the 3-month build-up phase of SIT, when modification of ICS doses was not allowed. During the 7 months of the maintenance phase of SIT, ICS doses were adjusted to control the asthma symptoms. RESULTS After 12 months of SIT, a reduction of the median daily ICS dose, necessary to control asthma symptoms, was 16.7% grater in patients from the placebo group than in patients from the montelukast group. Intervention with montelukast significantly impaired the induction of regulatory T lymphocytes. During the build-up phase of SIT, patients in the placebo group frequently experienced an increase in asthma symptoms leading to exclusions from the per protocol population. CONCLUSION Our study failed to show a beneficial effect of montelukast on SIT. In fact, quite the opposite occurred: compared with placebo, montelukast intervention led to less effectiveness of SIT.

Effect of Lactobacillus rhamnosus GG and vitamin D supplementation on the immunologic effectiveness of grass-specific sublingual immunotherapy in children with allergy.

BACKGROUND An important issue in sublingual immunotherapy (SLIT) is how to improve efficacy. OBJECTIVE To compare the clinical and immunologic efficacy of SLIT given alone and, to enhance clinical efficacy, given with probiotic or vitamin D supplementation. METHODS One hundred children, ages 5-12 years, sensitive to grass pollen, with allergic rhinitis participated in a 5-month prospective, randomized, double-blind, placebo-controlled trial. Children received 5-grass SLIT 300 IR tablets with either vitamin D 1000 IU daily supplementation, probiotic, or placebo. The control group included children with allergy who did not qualify for immunotherapy. Primary end points included a symptom-medication score, lung function, and exhaled nitric oxide concentration. The secondary end point was the immunologic efficacy measured by the following: CD4(+)CD25(+)Foxp3(+) (forkhead box P3) cells, Toll-like receptor (TLR) 4, interleukin (IL) 1, IL-6, tumor necrosis factor, IL-10, and transforming growth factor β-1 levels in cell culture supernatants. RESULTS Reduction in the symptom-medication score and improvement in lung function as well as a significant increase in the percentage of CD4(+)CD25(+)Foxp3(+) in children who received SLIT in all the groups were observed compared with control group. In the SLIT-probiotic group, between-group analysis showed significantly higher CD4(+)CD25(+)Foxp3(+) induction compared with the SLIT group and higher reduction in the percentage of TLR-positive cell group compared with the SLIT-vitamin D group (Fig. 1). An increase in CD4(+)CD25(+)Foxp3(+) induction, reduction in TLR-positive cells recruitment and an increase in transforming growth factor β-1 production were independently associated with a better clinical effect of SLIT in children. CONCLUSIONS We demonstrated the clinical and immunologic effect of probiotic and vitamin D supplementation on SLIT. Probiotic supplementation showed better clinical and immunologic response in children with allergic rhinitis.

Drug-selected cell line panels for evaluation of the pharmacokinetic consequences of multidrug resistance proteins.

Through the selection with five chemotherapeutics of diverse chemical structures and modes of action (cis-diamminedichloroplatinum, doxorubicin, etoposide, methotrexate and vincristine), four multidrug-resistant cell line panels were developed. Cancer cell lines of different species (human and murine) as well as tissue/organ (skin, colon) origin, characterized by low endogenous expression of multidrug resistance (MDR) proteins and high sensitivity to anticancer agents, were used as parental cell lines. A selection process resulted in the upregulation of several ABC transporters (ABCB1/Abcb1a, ABCC1/Abcc1 and ABCG2/Abcg2), which was confirmed by a number of molecular and cell biology methods. The MDR protein expression pattern seemed to be mainly dependent on the drug used for the selection and not on the species or tissue origin of the cell line. We postulate that such cell panels can be used as a research model to assess the role of MDR proteins in the pharmacokinetics of novel drugs or drug formulations.

Synthesis and Evaluation of In Vitro Biological Properties of Ferrocenyl Side-Chain-Decorated Paclitaxel

Taxanes, including paclitaxel, are widely used in cancer therapy. In an attempt to overcome some of the disadvantages entailed with taxane chemotherapy, we devised the synthesis of ferrocenyl‐functionalized paclitaxel derivatives and studied their biological properties. The cytotoxic activity was measured with a panel of human cancer cell lines of various tissue origin, including multidrug‐resistant lines. A structure–activity study of paclitaxel ferrocenylation revealed the N‐benzoyl‐ferrocenyl‐substituted derivative to be the most cytotoxic. In contrast, substitution of the 3′‐phenyl group of paclitaxel with a ferrocenyl moiety led to less potent antiproliferative compounds. However, these agents were able to overcome multidrug resistance, as they were virtually unrecognized by ABCB1, a major cellular exporter of taxanes. Interestingly, the redox properties of these ferrocenyl derivatives appear to play a less important role in their mode of action, as there was no correlation between intracellular redox activity and cytotoxicity/cell‐cycle distribution. The antiproliferative activity of ferrocenyl taxanes strongly depends on the substitution position, and good tubulin polymerization inducers, as confirmed by molecular docking, were usually more cytotoxic, whereas compounds with stronger pro‐oxidative properties exhibited lower antiproliferative activity.

Unusual Enhancement of Doxorubicin Activity on Co-Delivery with Polyhedral Oligomeric Silsesquioxane (POSS)

Polyhedral oligomeric silsesquioxane (POSS), bearing eight 3-chloroammoniumpropyl substituents, was studied as a potential nanocarrier in co-delivery systems with doxorubicin (DOX). The toxicity of doxorubicin and POSS:DOX complexes at four different molar ratios (1:1; 1:2, 1:4, 1:8) towards microvascular endothelial cells (HMEC-1), breast cancer cells (MCF-7), and human cervical cancer endothelial cells (HeLa) was determined. The rate of penetration of the components into the cells, their cellular localization and the hydrodynamic diameter of the complexes was also determined. A cytotoxicity profile of POSS:DOX complexes indicated that the POSS:DOX system at the molar ratio of 1:8 was more effective than free DOX. Confocal images showed that DOX co-delivery with POSS allowed for more effective penetration of doxorubicin through the cell membrane. Taking all the results into account, it can be claimed that the polyhedral oligomeric silsesquioxane (T8-POSS) is a promising, complex nanocarrier for doxorubicin delivery.