Treatment of Pancreatic Cancer by Aptamer Conjugated C/EBPα-saRNA

Pancreatic cancer is estimated to become the second-leading cause of cancer-related mortality by 2020. While the death rates of most other cancers continue to decline recently, the death rates of pancreatic cancer are still increasing, with less than 5% of patients achieving 5-year survival. Despite great efforts to improve treatment with combinational therapies in pancreatic cancer patients, limited progress has been made. V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) has been depicted as a therapeutic target in pancreatic cancer for many years. However, the clinical outcome of KRAS-directed therapies has not been successful, suggesting that KRAS is an undruggable target. For the new druggable target, epigenetically silenced transcriptional factor C/EBPα (CCAAT/enhancer-binding protein α), upregulator of a strong inhibitor of cell proliferation (p21), is upregulated by small activating RNA (saRNA) in pancreatic cancer. For the cell type-specific delivery, pancreatic cancer-specific 2'-Fluoropyrimidine RNA-aptamers (2'F-RNAs) are conjugated with C/EBPα-saRNA via sticky bridge sequences. The conjugates of aptamer-C/EBPα-saRNA upregulate the expression of C/EBPα in vitro and inhibit the tumor growth in vivo. It suggests that aptamer-mediated targeted delivery of therapeutic C/EBPα-saRNA might be the effective therapeutics under the current therapeutic modality failure in pancreatic cancer.

Comparison of marbling fleck characteristics between beef marbling grades and its effect on sensory quality characteristics in high-marbled Hanwoo steer

The aim of this study was to compare the intramuscular fat (IMF) content and marbling fleck characteristics measured by computerized image analysis among the eight grades of Korean beef marbling standard (BMS). Additionally, this study examined the effects of the marbling fleck characteristics on objective tenderness parameters and sensory quality characteristics in high-marbled Hanwoo steers (BMS grades 7 to 9). Marked differences were observed in marbling fleck characteristics among the BMS grades (P < .05), whereas the coarseness was similar in high-marbled beef (P > .05). Due to a greater extent of coarse marbling fleck, coarse marbled steaks from high-marbled cattle were assigned higher scores of tenderness attributes, including softness, initial tenderness, and chewiness, as well as mouth coating, but were assigned lower acceptability ratings for IMF content and overall impression compared to fine marbled steaks (P < .05). Taken together, considering the marbling fleck traits can be an effective tool for improving the accuracy of beef grading systems.

Abstract P2-07-10: Not presented

This abstract was not presented at the conference.

Citation Format: Lee H-B, Kim KE, Ju YW, Jung J-G, Ryu H-S, Lee SB, Lee JW, Lee HJ, Kim M-S, Kwon S, Kim J, Kim C, Moon H-G, Noh D-Y, Ahn S-H, Park I-A, Kim S, Yoon S, Kim A, Han W. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-07-10.

Therapeutic Potential of Small Activating RNAs (saRNAs) in Human Cancers

Background:

RNA is increasingly recognized as a powerful molecule that can be used to control gene expression. Sophisticated, well-engineered RNA-based regulators are being developed as oligotherapeutics.

Methods:

In particular, small activating RNAs (saRNAs) are promising therapeutic options for targeting human diseases. Numerous saRNAs targeting multiple cancers have been developed in preclinical models. One saRNA targeting C/EBPα is currently undergoing clinical trials in liver cancer.

Results and

Conclusion:

In this review, we describe the current working model of the intracellular mechanism of saRNA, discuss the recent progress of saRNA therapeutics in preclinical and clinical trials, and current advances in targeted delivery using aptamers in detail.

An RNA Aptamer Targeting the Receptor Tyrosine Kinase PDGFRα Induces Anti-tumor Effects through STAT3 and p53 in Glioblastoma

Human glioblastoma (GBM) is the most aggressive malignancy of the CNS, with less than 5% survival. Despite great efforts to find effective therapeutics, current options remain very limited. To develop a targeted cancer therapeutic, we selected RNA aptamers against platelet-derived growth factor receptor α (PDGFRα), which is a receptor tyrosine kinase. One RNA aptamer (PDR3) with high affinity (0.25 nM) showed PDGFRα specificity and was internalized in U251-MG cells. Following treatment with the PDR3 aptamer, expression of the transcription factor STAT3 (signal transducer and activator of transcription 3) was inhibited, whereas the expression of the histone demethylase JMJD3 and the tumor suppressor p53 were upregulated. PDR3 also upregulated serine phosphorylation of p53, which subsequently mediated apoptosis through the death receptors: tumor necrosis factor (TNF)-related apoptosis-inducing ligand receptors 1/2 (TRAIL-R1/R2), Fas-associated via death domain (FADD), and Fas. PDR3 significantly decreased cell viability in a dose-dependent manner. Furthermore, translocation of PDR3 into the nucleus induced hypomethylation at the promoters of cyclin D2. To assess the feasibility of targeted delivery, we conjugated PDR3 aptamer with STAT3-siRNA for a chimera. The PDR3-siSTAT3 chimera successfully inhibited the expression of target genes and showed significant inhibition of cell viability. In summary, our results show that well-tailored RNA aptamers targeting the PDGFRα-STAT3 axis have the potential to act as anti-cancer therapeutics in GBM.

Utility of the laryngeal handshake method for identifying the cricothyroid membrane

BACKGROUND

The cricothyroid membrane is the most commonly accessed location for invasive surgical airway. Although the laryngeal handshake method is recommended for identifying the cricothyroid membrane, there is no clinical data regarding the utility of the laryngeal handshake method in cricothyroid membrane identification. The objective of this study was to compare the accuracy of cricothyroid membrane identification between the laryngeal handshake method and simple palpation.

METHODS

After anaesthesia induction, the otorhinolaryngology resident and anaesthesia resident identified and marked the needle insertion point for cricothyroidotomy using simple palpation and the laryngeal handshake method, respectively. The cricothyroid membrane was confirmed with ultrasonography. Identification was determined successful if the marked point was placed within the longitudinal area of the cricothyroid membrane and within 5 mm from midline transversely. The accuracy of cricothyroid membrane identification using the laryngeal handshake method and simple palpation was compared.

RESULTS

A total of 123 patients were enrolled. The cricothyroid membrane was correctly identified in 87 (70.7%, 95% confidence interval 61.8-78.6%) patients using the laryngeal handshake method compared to 78 (63.4%, 95% confidence interval 54.3-71.9%) patients using simple palpation (P = .188). The time required to identify the cricothyroid membrane was longer when using the laryngeal handshake method (15 [3-48] seconds vs 10.9 [3-55] seconds, P = .003).

CONCLUSION

The success rate of identifying the cricothyroid membrane was similar among the anesthesiologists who performed the laryngeal handshake method and also among otorhinolaryngologists who used simple palpation.

Gene expression analysis of isolated salmonid GALT leucocytes in response to PAMPs and recombinant cytokines

Increased knowledge of the immune response of the intestine, a physiologically critical organ involved in absorption, secretion and homeostasis in a non-sterile environment, is needed to better understand the mechanisms involved in the induction of long-lasting immunity and, subsequently, the development of efficacious gastrointestinal immunization approaches. To this end, analysis of isolated gut cells will give an insight into the cell types present and their immune capability. Hence, in this study we first optimised a method for salmonid gut leucocyte isolation and characterised the cells on the basis of their expression of a range of selected cell markers associated with T & B cells and dendritic cells. The GALT leucocytes were then stimulated with a variety of PAMPs, recombinant cytokines and PHA, as a means to help characterise the diversity of the immune repertoire present in such cells. The stimulants tested were designed to examine the nature of the antibacterial, antiviral and T cell type responses in the cells (at the transcript level) using a panel of genes relevant to innate and adaptive immunity. The results showed distinct responses to the stimulants, with a clear delineation seen between the stimulant used (eg viral or bacterial PAMP) and the pathway elicited. The changes in the expression patterns of the immune genes in these cells indicates that the salmonid intestine contains a good repertoire of competent immune cells able to respond to different pathogen types. Such information may aid the development of efficient priming by oral vaccination in salmonids.

Aptamers: Uptake mechanisms and intracellular applications

The structural flexibility and small size of aptamers enable precise recognition of cellular elements for imaging and therapeutic applications. The process by which aptamers are taken into cells depends on their targets but is typically clathrin-mediated endocytosis or macropinocytosis. After internalization, most aptamers are transported to endosomes, lysosomes, endoplasmic reticulum, Golgi apparatus, and occasionally mitochondria and autophagosomes. Intracellular aptamers, or “intramers,” have versatile functions ranging from intracellular RNA imaging, gene regulation, and therapeutics to allosteric modulation, which we discuss in this review. Immune responses to therapeutic aptamers and the effects of G-quadruplex structure on aptamer function are also discussed.

Curriculum for neurogastroenterology and motility training: A report from the joint ANMS-ESNM task force

Although neurogastroenterology and motility (NGM) disorders are some of the most frequent disorders encountered by practicing gastroenterologists, a structured competency-based training curriculum developed by NGM experts is lacking. The American Neurogastroenterology and Motility Society (ANMS) and the European Society of Neurogastroenterology and Motility (ESNM) jointly evaluated the components of NGM training in North America and Europe. Eleven training domains were identified within NGM, consisting of functional gastrointestinal disorders, visceral hypersensitivity and pain pathways, motor disorders within anatomic areas (esophagus, stomach, small bowel and colon, anorectum), mucosal disorders (gastro-esophageal reflux disease, other mucosal disorders), consequences of systemic disease, consequences of therapy (surgery, endoscopic intervention, medications, other therapy), and transition of pediatric patients into adult practice. A 3-tiered training curriculum covering these domains is proposed here and endorsed by all NGM societies. Tier 1 NGM knowledge and training is expected of all gastroenterology trainees and practicing gastroenterologists. Tier 2 knowledge and training is appropriate for trainees who anticipate NGM disorder management and NGM function test interpretation being an important part of their careers, which may require competency assessment and credentialing of test interpretation skills. Tier 3 knowledge and training is undertaken by trainees interested in a dedicated NGM career and may be restricted to specific domains within the broad NGM field. The joint ANMS and ESNM task force anticipates that the NGM curriculum will streamline NGM training in North America and Europe and will lead to better identification of centers of excellence where Tier 2 and Tier 3 training can be accomplished.

Many Analysts, One Data Set: Making Transparent How Variations in Analytic Choices Affect Results

Twenty-nine teams involving 61 analysts used the same data set to address the same research question: whether soccer referees are more likely to give red cards to dark-skin-toned players than to light-skin-toned players. Analytic approaches varied widely across the teams, and the estimated effect sizes ranged from 0.89 to 2.93 ( Mdn = 1.31) in odds-ratio units. Twenty teams (69%) found a statistically significant positive effect, and 9 teams (31%) did not observe a significant relationship. Overall, the 29 different analyses used 21 unique combinations of covariates. Neither analysts’ prior beliefs about the effect of interest nor their level of expertise readily explained the variation in the outcomes of the analyses. Peer ratings of the quality of the analyses also did not account for the variability. These findings suggest that significant variation in the results of analyses of complex data may be difficult to avoid, even by experts with honest intentions. Crowdsourcing data analysis, a strategy in which numerous research teams are recruited to simultaneously investigate the same research question, makes transparent how defensible, yet subjective, analytic choices influence research results.