The heterogeneity of pancreatic ductal adenocarcinoma (PDAC) suggests that successful treatment might rely on simultaneous targeting of multiple genes, which can be achieved by RNA interference-based ...therapeutic strategies. Here we show a potent combination of microRNA and siRNA delivered by an efficient nanocarrier to PDAC tumors. Using proteomic-microRNA profiles and survival data of PDAC patients from TCGA, we found a novel signature for prolonged survival. Accordingly, we used a microRNA-mimic to increase miR-34a together with siRNA to silence PLK1 oncogene. For in vivo dual-targeting of this combination, we developed a biodegradable amphiphilic polyglutamate amine polymeric nanocarrier (APA). APA-miRNA-siRNA polyplexes systemically administered to orthotopically inoculated PDAC-bearing mice showed no toxicity and accumulated at the tumor, resulting in an enhanced antitumor effect due to inhibition of MYC oncogene, a common target of both miR-34a and PLK1. Taken together, our findings warrant this unique combined polyplex's potential as a novel nanotherapeutic for PDAC.
RNA interference (RNAi) can contribute immensely to the area of personalized medicine by its ability to target any gene of interest. Nevertheless, its clinical use is limited by lack of efficient ...delivery systems. Polymer therapeutics can address many of the challenges encountered by the systemic delivery of RNAi, but suffer from inherent drawbacks such as polydispersity and batch to batch heterogeneity. These characteristics may have far-reaching consequences when dealing with therapeutic applications, as both the activity and the toxicity may be dependent on the length of the polymer chain. To investigate the consequences of polymers' heterogeneity, we have synthesized two batches of aminated poly(α)glutamate polymers (PGAamine), differing in their degree of polymerization, but not in the monomer units or their conjugation. Isothermal titration calorimetry study was conducted to define the binding affinity of these polymers with siRNA. Molecular dynamics simulation revealed that Short PGAamine:siRNA polyplexes exposed a higher amount of amine moieties to the surroundings compared to Long PGAamine. This resulted in a higher zeta potential, leading to faster degradation and diminished gene silencing. Altogether, our study highlights the importance of an adequate physico-chemical characterization to elucidate the structure⁻function-activity relationship, for further development of tailor-designed RNAi delivery vehicles.
Small interfering RNA (siRNA) can silence the expression of a targeted gene in a process known as RNA interference (RNAi). As a consequence, RNAi has immense potential as a novel therapeutic approach ...in cancer targeted therapy. However, successful application of siRNA for therapeutic purposes is challenging due to its rapid renal clearance, degradation by RNases in the bloodstream, poor cellular penetration, immunogenicity and aggregation in the blood. In addition, the few oligonucleotide-based nanomedicines that reached clinical trials either go to the liver following systemic administration or are applied topically. Treatment of solid tumors requires selective distribution of siRNA to the target tissue, hence there is an unmet medical need for an efficacious and safe nano-sized delivery system for their clinical use. To overcome these hurdles, we have designed, synthesized and physico-chemically characterized a novel nanocarrier based on aminated poly(α)glutamate (PGAamine). This cathepsin B-biodegradable polymer interacts electrostatically with the siRNA to form a nano-sized polyplex stable in plasma. Treatment with PGAamine-Rac1 siRNA polyplex (siRac1-polyplex) caused specific gene silencing by 80% in HeLa and SKOV-3 human ovarian adenocarcinoma cells as opposed to PGAamine-control non-targeting siRNA polyplex (siCtrl-polyplex) leading to inhibition of cell migration and wound healing abilities. A stepwise dose escalation was performed in order to determine the in vivo maximum tolerated dose (MTD). This was followed by intraperitoneal administration of siRac1-polyplex to mCherry-labeled ovarian adenocarcinoma-bearing mice leading to preferred tumor accumulation of siRac1 (8-fold) which resulted in 38% Rac1 knockdown. Furthermore, the polyplex was administered intravenously to lung carcinoma-bearing mice in which it caused 33% Rac1 knockdown. These promising results led to efficacy studies administering systemic treatment with an anticancer siRNA, siPlk1-polyplex, which inhibited tumor growth by 73% and 87% compared with siCtrl-polyplex or saline-treated mice, respectively, leading to prolonged overall survival. These findings represent the first time that a polyaminated poly(α)glutamate polymer is used for an efficacious and safe tumor delivery of RNAi following systemic administration.
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It has been two decades since cationic polymers were introduced to the world of oligonucleotides delivery. However, the optimal physicochemical properties to make them a successful delivery vehicle ...are yet unknown. An ideal system became particularly interesting and necessary with the introduction of RNA interference as a promising therapeutic approach. Such nanocarrier should overcome challenges such as low plasma stability, poor cellular internalization and endosomal escape to induce gene silencing. To that end, we synthesized a library of biodegradable aminated poly(α)glutamate varied by amine moieties. In an attempt to elucidate the structure–function relationship, our polyplexes were physicochemically characterized and their silencing activity and cytotoxicity were evaluated. We found several structures that demonstrated improved cellular internalization. These candidates silenced gene expression to less than 50% of their initial levels, while being safe to cells and mice. Based on our research, an improved and promising tailor-designed siRNA delivery platform can be developed.
RNAi therapeutics carried a great promise to the area of personalized medicine: the ability to target “undruggable” oncogenic pathways. Nevertheless, their efficient tumor targeting via systemic ...administration had not been resolved yet. Amphiphilic alkylated poly(α)glutamate amine (APA) can serve as a cationic carrier to the negatively-charged oligonucleotides. APA polymers complexed with siRNA to form round-shaped, homogenous and reproducible nano-sized polyplexes bearing ~50 nm size and slightly negative charge. In addition, APA:siRNA polyplexes were shown to be potent gene regulators in vitro. In light of these preferred physico-chemical characteristics, their performance as systemically-administered siRNA nanocarriers was investigated. Intravenously-injected APA:siRNA polyplexes accumulated selectively in tumors and did not accumulate in the lungs, heart, liver or spleen. Nevertheless, the polyplexes failed to induce specific mRNA degradation, hence neither reduction in tumor volume nor prolonged mice survival was seen.
Amphiphilic poly(α)glutamate was synthesized and complexed with siRNA using a microfluidic chip. The obtained polyplex was physico-chemico-biologically characterized and optimized to shed light on the desired properties required for in vitro silencing efficacy. When intravenously administered to mammary-adenocarcinoma tumor-bearing mice, the polyplexes selectively accumulated at the tumor site. Display omitted
► Associations between risky behaviors of drivers and pedestrians were examined. ► Over 500 Israeli Ultra-Orthodox Jewish drivers and non-drivers participated. ► They completed questionnaires on risk ...taking as drivers and as pedestrians. ► Those who have a driver’s license are more likely to take risks as pedestrians. ► Associations were found between risky driving and risky behaviors as pedestrians.
This study examines associations between the risky behaviors of two types of road users: drivers and pedestrians. Whereas these behaviors have traditionally been investigated separately, the aim here was to examine the connection between them. The sample consisted of 518 drivers and non-drivers from the Ultra-Orthodox Jewish community in Israel (a sector in which having a driver’s license is not the norm), who completed a series of questionnaires relating to their tendency to take risks as drivers and as pedestrians. Results indicate that individuals who have a driver’s license are more likely to take risks as pedestrians than those who do not. In addition, among those with a driver’s license, strong correlations were found between various driving measures and the inclination for risky behaviors as pedestrians, indicating that the riskier the individual’s driving behavior, the more he or she tended to report dangerous pedestrian behavior. The findings suggest that different kinds of road-use behaviors are not entirely distinct from each other in respect to the degree of risk involved. Thus, the tendency to cross the road dangerously and the tendency to drive dangerously may reflect a more general propensity to take risks, at least in the context of road use.
The article examines the experiences of discrimination and racism and the individual coping strategies for dealing with them of 22 emerging adult Ethiopian immigrants in Israel. In-depth interviews ...explored how the participants feel, perceive, understand, respond to, and cope with discrimination. An initial qualitative analysis identified a gap between interviewees who denied the existence of racism and those who felt it acutely. Further analysis identified that those who denied the existence of racism applied one of two strategies: either denial of racism in general or a proactive strategy where the young person felt that his own behavior prevented racism. Two strategies were also identified among those who described frequent, painful experiences of racism: fighting back, which involved confronting or talking back to the perpetrator, and avoidance, choosing not to react to the situation. The article describes the different strategies and gives actual examples of the experiences. The results shed light on the experience of discrimination and coping with it and suggest that active coping mechanisms are connected to a more positive internal feeling and stronger feelings of belonging and integration, particularly when the strategy is based on acknowledgement that discrimination exists (as opposed to ignoring it).
חוויות של אפליה וגזענות ואסטרטגיות התמודדות אישיות עם חוויות אלה נבחנו בראיונות עומק עם 22 עולים יוצאי אתיופיה בוגרים-צעירים (emerging adults) בישראל. ניתוח איכותני ראשוני חשף הבדל בסיסי בין ...מרואיינים שהכחישו קיומה של אפליה, לבין אלה שחוויית האפליה הותירה בהם את רישומה. ניתוח נוסף, מעמיק ומפורט יותר, חשף עוד גוונים בכל אחת משתי האסטרטגיות העיקריות. בקרב אלה שהכחישו את קיומה של האפליה זוהו שתי אסטרטגיות נפרדות: הכחשה מוחלטת של האפליה ופרואקטיביות — התנהגות אישית המונעת את האפליה. זוהו גם שתי אסטרטגיות בקרב אלה שתיארו את האפליה כחוויה שכיחה: מאבק — עימות עם הגורם המפלה או תגובה אחרת כלפיו והימנעות — בחירה שלא להגיב בגלוי למעשה או למצב המפלה. המאמר מתאר את ארבע האסטרטגיות ואת החוויות הנקשרות אליהן בתהליך הקליטה וההשתלבות בחברה הישראלית. הממצאים מתארים ומדגימים את חוויית האפליה ואת סגנונות ההתמודדות עמה. עולה מהם שאסטרטגיות ההתמודדות הפעילות ננקטות על-ידי עולים בעלי תחושות פנימיות חיוביות יותר שחוו קליטה והשתלבות טובות יותר, בעיקר כשנלוותה אליהן מודעות לגזענות ולא התעלמות ממנה. The article examines the experiences of discrimination and racism and the individual coping strategies for dealing with them of 22 emerging adult Ethiopian immigrants in Israel. In-depth interviews explored how the participants feel, perceive, understand, respond to, and cope with discrimination. An initial qualitative analysis identified a gap between interviewees who denied the existence of racism and those who felt it acutely. Further analysis identified that those who denied the existence of racism applied one of two strategies: either denial of racism in general or a proactive strategy where the young person felt that his own behavior prevented racism. Two strategies were also identified among those who described frequent, painful experiences of racism: fighting back, which involved confronting or talking back to the perpetrator, and avoidance, choosing not to react to the situation. The article describes the different strategies and gives actual examples of the experiences. The results shed light on the experience of discrimination and coping with it and suggest that active coping mechanisms are connected to a more positive internal feeling and stronger feelings of belonging and integration, particularly when the strategy is based on acknowledgement that discrimination exists (as opposed to ignoring it).
In June 2010, Rabbi Shmuel Berezovsky, the Admor of Slonim, gave a sermon to thousands of supporters following the perceived triumph in the battle with the Supreme Court regarding the case of ...segregation in Emmanuel. The present paper suggests a detailed analysis of this homily, based on the assumption that its rhetoric reflects a certain attitude regarding the 'belonging' vs. 'alienation' of parts of the ultra-Orthodox community in Israel today. We explore the means of shaping the sermon, focusing on its structure and on the dialogue it carries on with previous texts in the Rebbe's cultural milieu. Our analysis reveals that the Rebbe presents the struggle as a battle between opposed archetypal forces, and between divergent physical and symbolic territories. Thus, the Rebbe seeks to fortify the discourse of his community as standing apart, while the legal triumph strengthens its autonomy. The motivation for this line of thought aligns with the classical inclination of the ultra-Orthodox establishment in its responses to perceived threats to their traditional identity and social frameworks. Adapted from the source document
To determine the time needed or the development of a positive result on the wrinkle test among patients with complete laceration of a digital nerve in a clinical setting. We prospectively recruited ...20 patients who had undergone surgery for digital nerve laceration. The wrinkle test was conducted at a follow-up session up to 2 months after surgery, and the time to a positive wrinkling result was recorded. The wrinkle test was compared between the patient's injured versus uninjured contralateral finger. The average time required for a positive result on the wrinkle test was 24.5 min (± 11), with 25% patients requiring 40 min to obtain a positive result. When evaluating a patient with digital nerve injury in a "non-laboratory" environment, the wrinkle test may require up to 40 min to obtain a positive result. Our study suggests that if tests are completed following the generally accepted time limit reported in the literature (30 min), up to 25% of tests may produce false negative results.
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