High Hemin Concentration Induces Escape from Senescence of Normoxic and Hypoxic Colon Cancer Cells.

Hemoglobin from either red meat or bowel bleeding may promote oxidative stress and increase the risk of colorectal cancer (CRC). Additionally, solid cancers or their metastases may be present with localized bruising. Escape from therapy-induced senescence (TIS) might be one of the mechanisms of tumor re-growth. Therefore, we sought to study whether hemin can cause escape from TIS in CRC. To induce senescence, human colon cancer cells were exposed to a chemotherapeutic agent irinotecan (IRINO). Cells treated with IRINO exhibited common hallmarks of TIS. To mimic bleeding, colon cancer cells were additionally treated with hemin. High hemin concentration activated heme oxygenase-1 (HO-1), induced escape from TIS and epithelial-to-mesenchymal transition, and augmented progeny production. The effect was even stronger in hypoxic conditions. Similar results were obtained when TIS cells were treated with another prooxidant agent, H2O2. Silencing of antioxidative enzymes such as catalase (CAT) or glutathione peroxidase-1 (GPx-1) maintained colon cancer cells in a senescent state. Our study demonstrates that a high hemin concentration combined with an increased activity of antioxidative enzymes, especially HO-1, leads to escape from the senescence of colon cancer cells. Therefore, our observations could be used in targeted anti-cancer therapy.

Polyploidy formation in cancer cells: How a Trojan horse is born.

Ploidy increase has been shown to occur in different type of tumors and participate in tumor initiation and resistance to the treatment. Polyploid giant cancer cells (PGCCs) are cells with multiple nuclei or a single giant nucleus containing multiple complete sets of chromosomes. The mechanism leading to formation of PGCCs may depend on: endoreplication, mitotic slippage, cytokinesis failure, cell fusion or cell cannibalism. Polyploidy formation might be triggered in response to various genotoxic stresses including: chemotherapeutics, radiation, hypoxia, oxidative stress or environmental factors like: air pollution, UV light or hyperthermia. A fundamental feature of polyploid cancer cells is the generation of progeny during the reversal of the polyploid state (depolyploidization) that may show high aggressiveness resulting in the formation of resistant disease and tumor recurrence. Therefore, we propose that modern anti-cancer therapies should be designed taking under consideration polyploidization/ depolyploidization processes, which confer the polyploidization a hidden potential similar to a Trojan horse delayed aggressiveness. Various mechanisms and stress factors leading to polyploidy formation in cancer cells are discussed in this review.

On the Question of Zwitterionic Intermediates in the [3 + 2] Cycloaddition Reactions between C-arylnitrones and Perfluoro 2-Methylpent-2-ene.

The molecular mechanism of the [3 + 2] cycloaddition reaction between C-arylnitrones and perfluoro 2-methylpent-2-ene was explored on the basis of DFT calculations. It was found that despite the polar nature of the intermolecular interactions, as well as the presence of fluorine atoms near the reaction centers, all reactions considered cycloaddition proceed via a one-step mechanism. All attempts for the localization of zwitterionic intermediates on the reaction paths were not successful. Similar results were obtained regardless of the level of theory applied.

ABCB1 Does Not Require the Side-Chain Hydrogen-Bond Donors Gln347, Gln725, Gln990 to Confer Cellular Resistance to the Anticancer Drug Taxol.

The multidrug efflux transporter ABCB1 is clinically important for drug absorption and distribution and can be a determinant of chemotherapy failure. Recent structure data shows that three glutamines donate hydrogen bonds to coordinate taxol in the drug binding pocket. This is consistent with earlier drug structure-activity relationships that implicated the importance of hydrogen bonds in drug recognition by ABCB1. By replacing the glutamines with alanines we have tested whether any, or all, of Gln347, Gln725, and Gln990 are important for the transport of three different drug classes. Flow cytometric transport assays show that Q347A and Q990A act synergistically to reduce transport of Calcein-AM, BODIPY-verapamil, and OREGON GREEN-taxol bisacetate but the magnitude of the effect was dependent on the test drug and no combination of mutations completely abrogated function. Surprisingly, Q725A mutants generally improved transport of Calcein-AM and BODIPY-verapamil, suggesting that engagement of the wild-type Gln725 in a hydrogen bond is inhibitory for the transport mechanism. To test transport of unmodified taxol, stable expression of Q347/725A and the triple mutant was engineered and shown to confer equivalent resistance to the drug as the wild-type transporter, further indicating that none of these potential hydrogen bonds between transporter and transport substrate are critical for the function of ABCB1. The implications of the data for plasticity of the drug binding pocket are discussed.

Microstructure and Optical Properties of Nanostructural Thin Films Fabricated through Oxidation of Au-Sn Intermetallic Compounds.

AuSn and AuSn2 thin films (5 nm) were used as precursors during the formation of semiconducting metal oxide nanostructures on a silicon substrate. The nanoparticles were produced in the processes of annealing and oxidation of gold-tin intermetallic compounds under ultra-high vacuum conditions. The formation process and morphology of a mixture of SnO2 and Au@SnOx (the core-shell structure) nanoparticles or Au nanocrystalites were carefully examined by means of spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectroscopy (EDX). The annealing and oxidation of the thin film of the AuSn intermetallic compound led to the formation of uniformly distributed structures with a size of ∼20-30 nm. All of the synthesized nanoparticles exhibited a strong absorption band at 520-530 nm, which is typical for pure metallic or metal oxide systems.

Escape From Cisplatin-Induced Senescence of Hypoxic Lung Cancer Cells Can Be Overcome by Hydroxychloroquine.

Chemotherapy is the commonly used treatment for advanced lung cancer. However, it produces side effects such as the development of chemoresistance. A possible responsible mechanism may be therapy-induced senescence (TIS). TIS cells display increased senescence-associated ß-galactosidase (SA-ß-gal) activity and irreversible growth arrest. However, recent data suggest that TIS cells can reactivate their proliferative potential and lead to cancer recurrence. Our previous study indicated that reactivation of proliferation by TIS cells might be related with autophagy modulation. However, exact relationship between both processes required further studies. Therefore, the aim of our study was to investigate the role of autophagy in the senescence-related chemoresistance of lung cancer cells. For this purpose, human and murine lung cancer cells were treated with two commonly used chemotherapeutics: cisplatin (CIS), which forms DNA adducts or docetaxel (DOC), a microtubule poison. Hypoxia, often overlooked in experimental settings, has been implicated as a mechanism responsible for a significant change in the response to treatment. Thus, cells were cultured under normoxic (~19% O2) or hypoxic (1% O2) conditions. Herein, we show that hypoxia increases resistance to CIS. Lung cancer cells cultured under hypoxic conditions escaped from CIS-induced senescence, displayed reduced SA-ß-gal activity and a decreased percentage of cells in the G2/M phase of the cell cycle. In turn, hypoxia increased the proliferation of lung cancer cells and the proportion of cells proceeding to the G0/G1 phase. Further molecular analyses demonstrated that hypoxia inhibited the prosenescent p53/p21 signaling pathway and induced epithelial to mesenchymal transition in CIS-treated cancer cells. In cells treated with DOC, such effects were not observed. Of importance, pharmacological autophagy inhibitor, hydroxychloroquine (HCQ) was capable of overcoming short-term CIS-induced resistance of lung cancer cells in hypoxic conditions. Altogether, our data demonstrated that hypoxia favors cancer cell escape from CIS-induced senescence, what could be overcome by inhibition of autophagy with HCQ. Therefore, we propose that HCQ might be used to interfere with the ability of senescent cancer cells to repopulate following exposure to DNA-damaging agents. This effect, however, needs to be tested in a long-term perspective for preclinical and clinical applications.

Influence of nasal mucosa irritants on the occurrence of chronic rhinosinusitis without /and with polyps.

<b>Introduction: </b>The aim of the study was to assess the effect of nasal mucosa irritants on the occurrence of chronic rhinosinusitis without/and with nasal polyps. <br><b>Material and methods:</b> The study involved 100 adult participants, including 39 women and 61 men, aged 21-68, diagnosed and treated at the Department of Otolaryngology, ENT Oncology, Audiology and Phoniatrics at the University Clinical Hospital WAM in Lódz. Based on the otorhinolaryngological and imaging (CT) tests they were divided into two groups: I - 50 patients, including 23 women and 27 men, aged 21-64 - with chronic rhinosinusitis without nasal polyps, II - 50 patients, including 16 women and 34 men, aged 22-68 - with chronic rhinosinusitis with nasal polyps. The control group consisted of 50 people (group III), including 25 women and 25 men, aged 18-30, students of the Faculty of Military Medicine at the Medical University of Lodz. All respondents completed a prepared questionnaire consisting of 17 questions addressed in the form of an anonymous interview among patients treated in the Department of Otolaryngology, ENT Oncology, Audiology and Phoniatrics. <br><b>Results:</b> The conducted surveys indicate the impact of the following factors in pathogenesis of chronic rhinosinusitis without/ with nasal polyps: exogenous factors (viruses, bacteria, fungi, drugs, injuries, toxic substances, environmental pollution), general endogenous factors (allergy, hypersensitivity to acetylsalicylic acid and its derivatives, hormonal disorders, supraesophageal reflux disease, granulation disease, immunity disorders, local endogenous factors. <br><b>Conclusions:</b> In the examined material, patients with chronic rhinosinusitis without/and nasal polyps in most cases are in the age range 51-60 years and over 60 years, they most often live in large cities over 250 thousand inhabitants, suffer from allergic rhinorhinitis in 38.0% in group I and 36.0% in group II, rapid temperature changes and dry air have a negative impact on comfort of breathing. The conducted surveys confirm that the cause of chronic rhinosinusitis with polyps is multifactorial, but a significant factor affecting typical tissue remodeling in this disease is long-term breathing of polluted atmospheric air.

Microstructure and Optical Properties of E-Beam Evaporated Zinc Oxide Films-Effects of Decomposition and Surface Desorption.

Zinc oxide films have been fabricated by the electron beam physical vapour deposition (PVD) technique. The effect of substrate temperature during fabrication and annealing temperature (carried out in ultra high vacuum conditions) has been investigated by means of atomic force microscopy, scanning electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy and spectroscopic ellipsometry. It was found that the layer deposited at room temperature is composed of Zn and ZnO crystallites with a number of orientations, whereas those grown at 100 and 200 ∘C consist of ZnO grains and exhibit privileged growth direction. Presented results clearly show the influence of ZnO decomposition and segregation of Zn atoms during evaporation and post-deposition annealing on microstructure and optical properties of zinc oxide films.

Comparison of factors influencing patient choice of community pharmacy in Poland and in the UK, and identification of components of pharmaceutical care.

BACKGROUND: Several factors, which are components of pharmaceutical care, can influence a patient's choice of a community pharmacy store and contribute to frequent visits to the same pharmacy. OBJECTIVES: To compare factors that influence a patient's choice of pharmacy in Poland and in the UK, to identify which of them are components of pharmaceutical care, and to relate them to patient loyalty to the same pharmacy. METHODS: A self-administered, anonymous questionnaire was distributed to clients visiting pharmacies in Poland and the UK January-August 2011. Comparisons were performed using chi-square tests and logistic regression. All statistical analyses were performed using SPSS 20.0. RESULTS: The response rate was 55.6% (n=417/750; 36 pharmacies) and 54.0% (n=405/750; 56 pharmacies) in Poland and in the UK, respectively. The most frequently reported factors, as defined by a percentage of responders, were in Poland: 1) location (84%); 2) professional and high-quality of service (82%); 3) good price of medicines (78%); and 4) promotions on medicines (66%). In the UK, the most commonly reported factors were: 1) professional and high quality of service (90%); 2) location (89%); 3) good advice received from the pharmacist (86%); and 4) option of discussing and consulting all health issues in a consultation room (80%). Good advice and an option of discussing personal concerns with a pharmacist are components of pharmaceutical care. Thirty-eight percent of patients in Poland and 61% in the UK declared visiting the same pharmacy. CONCLUSION: Components of pharmaceutical care are important factors influencing the patient's choice of pharmacy in the UK and, to a lesser degree, in Poland. Additionally, more patients in the UK than in Poland are committed to a single pharmacy. Therefore, implementing the full pharmaceutical care in Poland may contribute to an increase in patient loyalty and thus strengthen competitiveness of pharmacy businesses.