Targeted delivery of melittin to cancer cells by AS1411 anti-nucleolin aptamer

Melittin, a small water-soluble cationic amphipathic α-helical linear peptide, consisted of 26 amino acids, is the honeybee venom major constituent. Several reports have proved the lytic and apoptotic effects of melittin in several cancerous cell lines. In this study, we aimed to fabricate an AS1411 aptamer-melittin to specifically deliver melittin to nucleolin positive cells (A549). Melittin was covalently attached to antinucleolin aptamer (AS1411) and its toxicity in A549 (nucleolin positive) and L929 (nucleolin negative) was studied using MTT and Annexin V flow cytometry methods. Aptamer-melittin conjugate formation was confirmed by gel electrophoresis. Hemolytic effect of aptamer-melittin conjugate was compared to melittin alone. The aptamer-melittin conjugate showed efficient cell uptake and was more cytotoxic in A549 cells than melittin (p < .001). This complex was less toxic in control cells. Competitive inhibition assay confirmed that aptamer-melittin complex delivery occurred through receptor-ligand interaction on the cell surface. Moreover, aptamer-melittin showed a significantly less hemolytic activity as compared with free melittin. This study showed that melittin could be specifically delivered to A549 cells when it was covalently conjugated to antinucleolin aptamer (AS1411) in vitro. This system can reduce the cytotoxic effects of melittin on cells with no nucleolin receptor overexpression which comprise most of normal cells such as L929 cells.

Antitumour action on human glioblastoma A1235 cells through cooperation of bee venom and cisplatin

Cisplatin (cDDP) is one of the most widely used anticancer-drugs in both therapy and research. However, cDDP-resistance is the greatest obstacle for the successful treatment of cancer patients. In the present study, the possible joint anticancer effect of bee venom (BV), as a natural toxin, and cDDP towards human glioblastoma A1235 cells was evaluated. Treatment with BV alone in concentrations of 2.5-30 μg/ml displayed dose-dependent cytotoxicity towards A1235 cells, as evaluated with different cytotoxicity assays (MTT, Cristal violet and Trypan blue exclusion assay), with an IC50 value of 22.57 μg/ml based on the MTT results. Furthermore, BV treatment induced necrosis, which was confirmed by typical morphological features and fast staining with ethidium-bromide dye. Pre-treatment with BV induced cell sensitization to cDDP, indicating that BV could improve the killing effect of selected cells when combined with cDDP. The isobologram method used to determine the extent of synergism in combining two agents to examine their possible therapeutic effect showed that combined treatment induced an additive and/or synergistic effect towards selected cells depending on the concentration of both. Hence, a greater anticancer effect could be triggered if BV was used in the course of chemotherapy. The obtained results indicate that joint treatment with BV could be useful from the point of minimizing the cDDP concentration during chemotherapy, thus reducing and/or postponing the development of drug resistance. Our data, in accordance with previously reported results, suggests that BV could be used in the development of a new strategy for cancer treatment.

Melittin: a lytic peptide with anticancer properties

Melittin (MEL) is a major peptide constituent of bee venom that has been proposed as one of the upcoming possibilities for anticancer therapy. Recent reports point to several mechanisms of MEL cytotoxicity in different types of cancer cells such as cell cycle alterations, effect on proliferation and/or growth inhibition, and induction of apoptotic and necrotic cell death trough several cancer cell death mechanisms, including the activation of caspases and matrix metalloproteinases. Although cytotoxic to a broad spectrum of tumour cells, the peptide is also toxic to normal cells. Therefore its therapeutic potential cannot be achieved without a proper delivery vehicle which could be overcome by MEL nanoparticles that possess the ability to safely deliver significant amount of MEL intravenously, and to target and kill tumours. This review paper summarizes the current knowledge and brings latest research findings on the anticancer potential of this lytic peptide with diverse functions.

Study protocol of a randomized controlled trial to improve cancer prevention behaviors in adolescents and adults using a web-based intervention supplemented with SMS

Background

The overall number of cancer cases is increasing and, therefore, strengthening cancer prevention has become a priority. The institutions responsible for its control establish guidelines for primary prevention. These include recommendations, such as: not smoking, following a healthy diet, doing daily physical exercise or avoiding overweight. Adolescence is a period of adoption and/or consolidation of health behaviors, and both school- and family-based interventions have proven effective to improve them. Furthermore, online and mobile phone educational interventions are encouraging. Consequently, the main aim of this study is to assess the efficacy of an intervention in which these requirements (school, family, the Internet and SMS) are combined to prevent behavioral cancer risk.

Methods

This protocol describes the design and implementation of a complex online program that includes a randomized controlled trial put into practice in two countries: Spain and Mexico. Adolescents and adults of their environment (relatives and teachers) who voluntarily participate will be randomly assigned to the experimental group or to the control group once they have completed the online pre-test. The experimental group members will have free access to a tailor-made and interactive website (http://www.alertagrumete.com). During the academic year, this website will be periodically updated with different school and leisure activities related to the avoidance of risk behaviors. To encourage participation, the program includes a competition that gives rewards to the winners. SMS are also sent to students to stimulate the adoption of healthy behaviors and as a reminder of participation. Finished the intervention, an online post-test is performed in both groups and the impact on the risk behaviors is therefore assessed.

Discussion

The program is pioneer, since it combines many components which have already proven effective in previous researches. Moreover, it aims to compare efficacy in two countries with different socio-economic levels to find out if these approaches are equally effective in countries with a lower income level. However, the vertiginous evolution of the Internet and mobile phones may make this tool less attractive for adolescents, who may prefer social networks and other mobile phone applications which are nowadays massively used by their peers.

Trial registration

ISRCTN27988779

Effect of self-administered auricular acupressure on smoking cessation--a pilot study

Background

Tobacco smoking is still a worldwide health risk. Current pharmacotherapies have at best, a success rate of no more than 50%. Auricular (ear) acupressure has been purported to be beneficial in achieving smoking cessation in some studies, while in others has been deemed insignificant. We hereby describe the protocol for a three-arm randomised controlled trial to examine the possible benefits of self-administered acupressure for smoking cessation.

Methods

Sixty consenting participants with confirmed habit of tobacco smoking will be recruited and randomized into three arms to receive either auricular acupressure at five true acupoints (NADA protocol), auricular acupressure at five sham points, or no auricular acupressure at all. Participants having auricular acupressure will exert firm pressure to each acupoint bilaterally via the bead in the attached plasters whenever they feel the urge to smoke. The treatment phase will last for six weeks during which all participants will be assessed weekly to review their smoking log, state of abstinence, end-exhalation carbon monoxide levels and possible adverse effects including withdrawal reactions and stress levels. At any time, a successful quit date will be defined with continuous abstinence for the following consecutive 7 days. From then on, participants will be evaluated individually for continuous abstinence rate (CAR), end-exhalation carbon monoxide levels and adverse effects of stress and withdrawal at specified intervals up to 26 weeks. Expectancy of treatment will be assessed with a four-item Borkovec and Nau self-assessment credibility scale during and after intervention.

Discussion

We incorporate validated outcome measures of smoking cessation into our randomised controlled trial design with the objectives to evaluate the feasibility and possible benefits of self-administered auricular acupressure as a non-invasive alternative to pharmacotherapy for smoking cessation.

Trial Registration

ClinicalTrials.gov: NCT01389622 (registered Jul 7 2011)

Presence of phthalate esters in intravenous solution evaluated using gas chromatography-mass spectrometry method

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the production of poly-(vinyl) chloride (PVC) materials. It is a reproductive and developmental toxicant in animals and a suspected endocrine modulator in humans. DEHP is not covalently bound within the PVC molecule, which is why migration into a suitable medium can be expected. Since application of infusion solutions is one of the most common medical treatments, the objective of this study was to determine the migration of phthalates from softened PVC storage bags into infusion solution in different time periods within one year from date of production using a gas chromatography-mass spectrometry method. The measured values of DEHP ranged between 0.22 and 14.00 µg l(-1) , but the unexpected presence of other phthalate esters was also detected. It was concluded that values obtained in infusion solutions match the reference data and represent a minor risk for the patient. The presence of other phthalate esters leads to the conclusion that the pharmacopeic requirement for polymer cleanness was not fully met. Since phthalate esters are among the most extensively used industrial chemicals and are widely distributed in the environment, special precautions and further monitoring should be conducted to minimize any possible health risks.

In vitro and in vivo evaluation of the anticarcinogenic and cancer chemopreventive potential of a flavonoid-rich fraction from a traditional Indian herb Selaginella bryopteris

Prevention of cancer through nutritional intervention has gained significant recognition in recent years. Evidence revealed from mechanistic investigations coupled with molecular epidemiology show an inverse association of dietary flavonoids intake with cancer risk. The chemopreventive and anticarcinogenic potential of Selaginella bryopteris, a traditional Indian herb referred to as ‘Sanjeevani’ in the Ayurvedic system of medicine, was examined in the present study. Comprehensive in vitro and in vivo studies were conducted on the flavonoid-rich benzene fraction of the aqueous extract that demonstrated a significant cytoprotective activity. Biomarkers of chemoprevention such as proliferative index and status of cell-cycle regulatory proteins, antioxidant property, anti-inflammatory effect, reversal of stress-induced senescence and genoprotective effect were investigated in human and murine cell cultures. Chemopreventive potential was assessed in benzopyrene-induced lung carcinogenesis and 7,12-dimethyl benz(a)anthracene-mediated skin papillomagenesis test models. Inhibition of DNA fragmentation, unperturbed cell-cycle regulation, maintenance of intracellular antioxidant defence, anti-inflammatory activity, prevention of stress-induced senescence and genoprotective effects against methyl isocyanate carcinogenicity was observed. Medium-term anticarcinogenicity and two-stage skin papillomagenesis tests strongly substantiated our in vitro observations. Results from the present study provide evidence of anticarcinogenic and chemopreventive activities of S. bryopteris hitherto unreported and reaffirm the nutritional significance of flavonoids in cancer prevention.