Efficacy of Asymmetric siRNA Targeting Androgen Receptors for the Treatment of Androgenetic Alopecia.

Asymmetric small interfering RNAs (asiRNAs) that mediate RNA interference have been investigated for therapeutic use in various tissues, including skin tissue. Androgenetic alopecia (AGA) is caused by a combination of genetic factors, resulting in sensitivity to dihydrotestosterone (DHT), which binds to the androgen receptor (AR) to mediate a series of biomolecular changes leading to hair loss. This study aimed to evaluate the therapeutic potential of a cell-penetrating, AR-targeting asiRNA (cp-asiAR) for AGA treatment, which was designed to silence the AR gene. AGA mouse models were developed by stimulation with DHT, and ex vivo human scalp tissues were also used for analysis. Cp-asiAR-mediated changes in mRNA expression and protein levels of AR were assessed along with the examination of phenotypic improvements in mouse model of AGA. We also assessed downstream signaling associated with AR in primary human dermal papilla (DP) cells. Several cp-asiARs were screened for selecting the optimal sequence of AR using cell lines in vitro. A cholesterol-conjugated, chemically modified cp-asiAR candidate was optimized under passive uptake conditions in vitro. Intradermal cp-asiAR injection efficiently reduced mRNA and protein levels corresponding to AR in mouse models. Moreover, cp-asiAR injection promoted hair growth in mouse models with DHT-induced AGA. In ex vivo human hair follicle culture, the proportion of telogen hair decreased, and the mean hair bulb diameter increased in the cp-asiAR-treated group. In isolated primary human DP cells, AR expression was effectively downregulated by cp-asiAR. Furthermore, cp-asiAR attenuated DHT-mediated increases in interleukin-6, transforming growth factor-ß1, and dickkopf-1 levels. No significant toxicity was observed in DP cells after cp-asiAR treatment. Cp-asiAR treatment showed effective downregulation of AR expression and prevention of DHT-mediated alterations in the hair cycle and hair diameter, indicating its potential as a novel therapeutic option for AGA.

Reliability and validity of the Self-Efficacy in Palliative Care Scale among nurses.

OBJECTIVES: To provide appropriate palliative care, nurses should have appropriate level of self-efficacy in palliative care, but the levels among nurses were low. To improve the levels effectively, self-efficacy in palliative care should be assessed using reliable and valid instruments. The purpose of this study was to examine the reliability and validity of the Self-Efficacy in Palliative Care Scale in Korean nurses. METHODS: In this cross-sectional, observational study, 272 nurses (mean age: 30 years) were enrolled from 6 university-affiliated medical centers or community hospitals in South Korea. Data on self-efficacy and demographic characteristics were collected. Validity was assessed by exploratory and confirmatory factor analyses (SPSS and Mplus). Reliability and homogeneity were assessed by Cronbach's alpha and item analyses (SPSS), respectively. RESULTS: The exploratory and confirmatory factor analyses supported the 4-factor structure (communication, assessment and symptom management, psychosocial and spiritual management of patient and family, and multiprofessional teamworking) with factor loadings >.60 and with good model fit: root mean square error of approximation =.07, Tucker-Lewis index =.94, comparative fit index =.95, and standardized root mean square residual =.04. Cronbach's alphas for the total scale and each of the subscales ranged from .883 to .965. The corrected item-total correlation coefficients of all items ranged from .61 to .90. SIGNIFICANCE OF RESULTS: The findings of this study supported the reliability and validity of this instrument among Korean nurses. This instrument can be used to assess nurses' self-efficacy in palliative care and to test intervention effects on it.

Psychometric properties of the end-of-life care decision inventory (EOL-CDI): a mixed-methods study.

BACKGROUND: End-of-life care decision-making has become important to support dignity and quality of life for patients who are facing death in Korea, along with the enactment of the Life-Sustaining Treatment Act in 2018. However, it seems that the concepts and policies related to the law are not yet familiar to health care providers or the general public. This unfamiliarity can hinder efficient end-of-life care discussions. Therefore, the purpose of this study was to propose a valid and reliable tool to explore the level of understanding of concepts and attributes related to end-of-life care decisions. METHODS: This is a mixed-methods study design. A relevant law and literature analysis, expert consultation, cognitive interviews of 10 adults, and cross-sectional survey for psychometric tests using data from 238 clinical nurses were performed to update a tool developed before the life-sustaining treatment Act was enacted in Korea. RESULTS: 29 items of the draft version were polished in terms of literacy, total length, and scoring method via cognitive interviews and finalized into 21 items through psychometric tests and expert consultations. The 21 items conformed to the Rasch unidimensional paramenters. CONCLUSION: A tool to identify the level of understanding of concepts related to end-of-life care decisions was proposed through a rather rigorous process to ensure feasibility and validity/reliability. We recommend the proposed tool to apply to the adult population and nurses for evaluation and educational purposes.

Emergency Healthcare Providers' Knowledge about and Attitudes toward Advance Directives: A Cross-Sectional Study between Nurses and Emergency Medical Technicians at an Emergency Department.

This study aimed to explore and compare knowledge levels about advance directives (ADs) and life-sustaining treatment (LST) plans in end-of-life patients between emergency nurses and emergency medical technicians (EMTs). Using a cross-sectional study design and convenience sampling, 96 nurses and 68 EMTs were recruited from 12 emergency medical centers. A survey on knowledge about and attitudes toward ADs was performed using both online and offline methods between November and December 2019. Emergency healthcare providers were conceptually knowledgeable regarding ADs and LST, although approximately half or fewer had knowledge about ADs (such as the legal process for preparation, family or healthcare providers' role, and the healthcare proxy). The knowledge levels of nurses and EMTs were moderate. Nurses had significantly greater knowledge relative to EMTs about ADs and LST. Positive attitudes of emergency healthcare providers were also moderately low, with nurses having less positive views than EMTs. Significant differences regarding ADs were found, with younger emergency healthcare providers having fewer career years, no personal end-of-life experiences, and less need for ADs having less knowledge. Emergency healthcare providers' knowledge about and attitudes toward ADs were moderately low, with EMTs demonstrating a greater knowledge deficit and nurses exhibiting lower positive attitudes. Younger and novice providers had lower knowledge, but younger providers had more positive attitudes, implying that professional education and training should begin early in their careers to enhance their confidence for emergency delivery of advanced care planning.

Psychometric Testing of the Korean Version of the Attitudes toward the Advance Directives in Low-Income Chronically Ill Older Adults.

The purpose of this study was to examine the psychometric properties of the Advance Directive Attitude Survey in Korean (K-ADAS), a measure of attitudes toward advance directives (ADs). A total of 118 low-income, community-dwelling older adults (mean age, 75.09 years) participated. An exploratory factor analysis (EFA) was conducted to determine the factor structure of the K-ADAS. Validity was further assessed by known associations of the K-ADAS with perceived susceptibility and severity using part of the Advance Care Planning surveys. Its reliability was examined by calculating alpha coefficients. EFA determined a three-factor structure model with good model fit. Validity was further supported with significant correlations between the K-ADAS and susceptibility and severity. Reliability was supported by adequate level of Cronbach's alpha. The K-ADAS was a valid and reliable measure for assessment of AD attitudes with a sound model fit. Thus, the K-ADAS can be used to assess AD attitudes among community-dwelling elders.

L-Type Calcium Channel Blocker Enhances Cellular Delivery and Gene Silencing Potency of Cell-Penetrating Asymmetric siRNAs.

The efficient delivery of small interfering RNAs (siRNAs) to the target cells is critical for the pharmaceutical success of RNA interference (RNAi) drugs. One of the possible strategies to improve siRNA delivery is to identify auxiliary molecules that augment their cellular uptake. Herein, we performed a chemical library screening in an effort to discover small molecules that enhance the potency of cholesterol-conjugated, cell-penetrating asymmetric siRNAs (cp-asiRNAs). Interestingly, three compounds identified from the screen share a common dihydropyridine (DHP) core and function as L-type calcium channel blockers (CCBs). Using confocal microscopy and quantitative analysis of small RNAs, we demonstrated that the L-type CCBs increased the endocytic cellular uptake of cp-asiRNAs. Furthermore, these small molecules substantially improved the potency of cp-asiRNAs, not only in vitro but also in vivo on rat skin. Collectively, our study provides an alternative pharmacological approach for the identification of small molecules that potentiate the effects of therapeutic siRNAs.

Validity and Reliability of the Life Transition Scale in Parents of Disabled Children Across the Life Transition Process.

PURPOSE: The Life Transition Scale (LTS) consists of 24 items that assess the life transition process of parents of autistic children. This study aimed to examine the validity and reliability of the LTS in parents of children with a wide spectrum of disabilities. METHODS: Data were collected from 260 parents of children with disabilities through self-report questionnaires. Validity was examined using exploratory and confirmative factor analysis to determine the factor structures of the LTS; socio-demographic differences in LTS scores were examined using the t-test or ANOVA. Reliability was examined using Cronbach's ⍺ coefficient. RESULTS: A four-factor structure was validated (x 2=640.0, p<.001, GFI=.81, RMSEA=.07, NNFI=.89, CFI=.89, PNFI=.74, Q [x 2/df]=2.60). The validity of the LTS was verified by exploratory factor analysis, with factor loading ranging from .30 to .80. There were significant differences in the accepting phase according to children's and parents' age and the type of disability, and in the wandering phase according to parental gender, educational level, job, and socioeconomic status. The Cronbach's ⍺s for the reliability of each of the four structures were acceptable, within a range of .80~.90. CONCLUSION: The LTS is a valid and reliable measurement to assess the life transition process of parents with disabled children.

Correlates of advance directive treatment preferences among community-dwelling older people with chronic diseases.

BACKGROUND: Concerns over the creation of advance directives (ADs) and the factors associated with treatment directive decisions among Korean community-dwelling older people with chronic diseases have rarely been addressed. OBJECTIVES: This study aimed to examine knowledge, attitudes and barriers/benefits regarding ADs and their associations with AD treatment preferences among chronically ill, low-income, community-dwelling older people. METHODS: Using a descriptive, correlational design, older people who were recipients of home visiting service for chronic disease management participated in this study. Home visiting nurses collected data on knowledge, attitudes and perceived barriers/benefits and treatment directives using questionnaires during home visits. RESULTS: Older people (N = 112, mean age = 74.9 years, women = 83.9%) who had chronic diseases such as hypertension (56.3%), diabetes mellitus (40.2%) and cardiovascular disease/stroke (22.3%) participated. Approximately half of the participants preferred hospice care (54.5%), while a few of them preferred aggressive treatments: cardiopulmonary resuscitation (CPR) (14.3%), ventilation support (9.8%) and haemodialysis (8.9%). Being married was associated with the likelihood of preferring CPR (odds ratio [OR] = 11.79) and ventilation support (OR = 9.99), higher education with CPR (OR = 1.23) and haemodialysis (OR = 1.16), and having a cardiovascular disease (CVD)/stroke with CPR (OR = 6.46) and hospice care (OR = 3.06). Among the modifiable factors, greater perceived barriers increased the likelihood of CPR preference (OR = 1.12) but decreased the likelihood of hospice care preference (OR = 0.96). Greater perceived benefits decreased the likelihood of CPR preference (OR = 0.81) and ventilation support (OR = 0.89), and AD knowledge decreased the likelihood of haemodialysis preference (OR = 0.23). CONCLUSION: The multidimensional factors were differently associated with each of the AD treatment preferences. Modifiable factors, including perceived barriers and benefits and knowledge, should be improved to help low-income, community-dwelling older people select adequate AD treatment preferences. IMPLICATIONS FOR PRACTICE: Additional information regarding AD treatments and some modifiable and non-modifiable correlates can be integrated into primary and palliative/supportive care in public health. The current home visitation service may also benefit from incorporating AD discussions while extending the service to embrace AD issues in addition to disease management.

RNA Interference-Mediated Gene Silencing by Branched Tripodal RNAs Does Not Require Dicer Processing.

Specific gene silencing through RNA interference (RNAi) holds great promise as the next-generation therapeutic development platform. Previously, we have shown that branched, tripodal interfering RNA (tiRNA) structures could simultaneously trigger RNAi-mediated gene silencing of three target genes with 38 nt-long guide strands associated with Argonaute 2. Herein, we show that the branched RNA structure can trigger effective gene silencing in Dicer knockout cell line, demonstrating that the Dicer-mediated processing is not required for tiRNA activity. The finding of this study confirms the flexibility of the structure of RNAi triggers as well as the length of the guide strand in RNAi-mediated gene silencing.

Feasibility of the Korean-Advance Directives Among Community-Dwelling Elderly Persons.

A newly developed Korean-Advance Directive (K-AD) consists of a value statement, treatment directives, and proxy appointment. It remains undetermined whether K-AD is applicable to community-dwelling persons (≥ aged 60 years). Using a descriptive study design, 275 elderly persons completed the K-AD (mean age = 77.28 ± 8.24 years). The most frequent value at the end of life was comfort dying, followed by no burden to family (23.6%). Among 4 K-AD treatment options, more than half had a preference for hospice care and had reluctance with aggressive treatment choices of cardiopulmonary resuscitation (76.4%), artificial ventilation (75.6%), and tube feeding (76.4%), with one-fifth having a desire for such options. All persons provided proxies, who were predominantly descendants (77.1%), followed by spouses (17.5%). For treatment preferences, men and those with no religion were more likely to receive life-sustaining treatments. These data support the K-AD as being applicable and acceptable among community-dwelling elderly persons; awareness of the K-AD in the community setting may facilitate future application when the need occurs.

Validation of the Decisional Conflict Scale for Evaluating Advance Care Decision Conflict in Community-dwelling Older Adults.

PURPOSE: Decisional conflict is a significant and important barrier in end-of-life care planning, and it is often encountered in health professionals' discussions with patients and their families. Little is known about the measurement of decisional conflict, and existing measures are not suitable for all contexts. In this study, psychometric properties of the Decisional Conflict Scale, which was translated for the first time into Korean [Korean version of DCS (K-DCS)], were examined. METHODS: A sample of 273 community-dwelling elders was surveyed (mean age: 77.26 years; 80.2% women). Internal consistency reliability and stability reliability were tested by calculating Cronbach α and Pearson's correlation coefficients. Exploratory factor analysis and logistic regression analyses were performed to test validity. RESULTS: Reliability of the K-DCS was acceptable with Cronbach α =.87; test-retest correlation r = .76. Factor analysis showed a two-factor structure with nine items: informed/values clarity and uncertainty. Concordance between K-DCS and the four treatment directives was significant (kappa values ≥.78). Controlling for age and gender, those with decision implementation were more likely to implement their decisions on tube feeding (odds ratio = 5.15, p = .033) and hospice care (odds ratio = 2.83, p = .017). CONCLUSION: The K-DCS appears to be a valid measure to evaluate decisional conflict about advance directives in community-dwelling Korean older adults. Further validation of the K-DCS is warranted, though caution should be exercised in using subscales because of differences in decisional contexts.

Development of Cell-Penetrating Asymmetric Interfering RNA Targeting Connective Tissue Growth Factor.

Connective tissue growth factor (CTGF) is a multifunctional matricellular protein, playing a role as a central mediator in tissue remodeling and fibrosis. A number of reports have shown the pivotal roles of CTGF in the progression of fibrosis, suggesting CTGF as a promising therapeutic target for the treatment of fibrotic disorders including hypertrophic scars and keloids. In this study, we present the development of an interfering RNA molecule that efficiently inhibits the expression of CTGF via RNA interference mechanism both in vitro and in vivo. Chemical modifications were introduced to the asymmetric interfering RNA (asiRNA) backbone structure. The resulting RNA molecule, termed cell-penetrating asiRNA (cp-asiRNA), entered into cells and triggered RNA interference-mediated gene silencing without delivery vehicles. The gene-silencing activity of cp-asiRNA targeting CTGF (cp-asiCTGF) was examined both in vitro and in vivo. Furthermore, the administration of cp-asiCTGF in the rat skin excision wound model efficiently reduced the induction of CTGF and collagens during the wound-healing process. These results suggest that the cp-asiCTGF molecule could be developed into antifibrotic therapeutics such as antiscar drugs.

Understanding the molecular aspects of oriental obesity pattern differentiation using DNA microarray.

BACKGROUND: Human constitution, the fundamental basis of oriental medicine, is categorized into different patterns for a particular disease according to the physical, physiological, and clinical characteristics of the individuals. Obesity, a condition of metabolic disorder, is classified according to six patterns in oriental medicine, as follows: spleen deficiency syndrome, phlegm fluid syndrome, yang deficiency syndrome (YDS), food accumulation syndrome (FAS), liver depression syndrome (LDS), and blood stasis syndrome. In oriental medicine, identification of the disease pattern for individual obese patients is performed on the basis of differentiation in obesity syndrome index and, accordingly, personalized treatment is provided to the patients. The aim of the current study was to understand the obesity patterns in oriental medicine from the genomic point of view via determining the gene expression signature of obese patients using peripheral blood mononuclear cells as the samples. METHODS: The study was conducted in 23 South Korean obese subjects (19 female and four male) with BMI ≥25 kg/m(2). Identification of oriental obesity pattern was based on the software-guided evaluation of the responses of the subjects to a questionnaire developed by the Korean Institute of Oriental Medicine. The expression profiles of genes were determined using DNA microarray and the level of transcription of genes of interest was further evaluated using quantitative real-time PCR (qRT-PCR). RESULTS AND CONCLUSION: Gene clustering analysis of the microarray data from the FAS, LDS, and YDS subjects exhibited disease pattern-specific upregulation of expression of several genes in a particular cluster. Further analysis of transcription of selected genes using qRT-PCR led to identification of specific genes, including prostaglandin endoperoxide synthase 2, G0/G1 switch 2, carcinoembryonic antigen-related cell adhesion molecule 3, cystein-serine-rich nuclear protein 1, and interleukin 8 receptor, alpha which were highly expressed in LDS obesity constitution. Our current study can be considered as a valuable contribution to the understanding of possible explanation for obesity pattern differentiation in oriental medicine. Further studies can address a novel possibility that the genomic and oriental empirical approaches can be combined and implemented in systematic and synergistic development of personalized medicine. This clinical trial was registered in Clinical Research Information Service of Korea National Institute of Health ( https://cris.nih.go.kr/cris/index.jsp ). REGISTRATION NUMBER: KCT0000387.

[Construct validity of the life transition scale for parents of children with autism].

PURPOSE: The study was done to identify the construct validity and reliability of the life transition scale (LTS) for parents who have children with autism. METHODS: Exploratory factor analysis (EFA) and confirmative factor analysis (CFA) were conducted to identify the most adequate measurement model for structural validity. Convergent validity and discriminant validity were also conducted for structural validity. Data were collected from 208 parents through self-reported questionnaires and analyzed with SPSS/WIN 15.0 and AMOS 20.0 version. RESULTS: A four factor-structure was validated (χ²=541.23, p<.001, GFI=.82, RMSEA=.07, IFI=.89, CFI=.89, PNFI=.73, Q (χ²/df)=2.20) at the 3rd order of EFA and CFA, and factors were named as denying, wandering, despairing, and accepting. Both convergent and determinant validity for LTS were 100%. Cronbach's alphas for the reliability of each structure were .77-.90 and .83 for total structure. CONCLUSION: The four structures, 24-item instrument showed satisfactory reliability and validity. LTS has the potential to be appropriate for assessing the transition process of life for parents who have children with autism and provides basic directions for differentiated support and care at each stage.

Efficient intracellular delivery and multiple-target gene silencing triggered by tripodal RNA based nanoparticles: a promising approach in liver-specific RNAi delivery.

RNA interference (RNAi) triggering oligonucleotides in unconventional structural format can offer advantages over conventional small interfering RNA (siRNA), enhanced cellular delivery and improved target gene silencing. With this concept, we present a well-defined tripodal-interfering RNA (tiRNA) structure that can induce simultaneous silencing of multiple target genes with improved potency. The tiRNA structure, formed by the complementary association of three single-stranded RNA units, was optimized for improved gene silencing efficacy. When combined with cationic polymers such as linear polyethyleneimine (PEI), tiRNA assembled to form a stable nano-structured complex through electrostatic interactions and induced stronger RNAi response over conventional siRNA-PEI complex. In combination with a liver-targeting delivery system, tripodal nucleic acid structure demonstrated enhanced fluorescent accumulation in mouse liver compared to standard duplex nucleic acid format. Tripodal RNA structure complexed with galactose-modified PEI could generate effective RNAi-mediated gene silencing effect on experimental mice models. Our studies demonstrate that optimized tiRNA structural format with appropriate polymeric carriers have immense potential to become an RNAi-based platform suitable for multi-target gene silencing.

Effect of siRNA with an asymmetric RNA/dTdT overhang on RNA interference activity.

Small interfering RNAs (siRNAs) guide RNA-induced silencing complexes (RISC) to target mRNAs for sequence-specific silencing. A fundamental aspect of this highly coordinated process is a guide strand-specific loading of the siRNA duplex into the RISC for the accurate target recognition, which is currently dictated by certain duplex parameters such as thermodynamics. Here, we show that minor changes in the overhang structure have profound effects on the extent to which the individual strands of the siRNA duplex participate in RNAi activity. We demonstrate that the two strands of the siRNA are similarly eligible for assembly into RISC for the siRNAs with symmetric overhangs, whereas those with asymmetric RNA/deoxythymidine dinucleotide (dTdT) overhangs exhibit a distinct preference in favor of a strand with an RNA overhang that drives a mature RISC affinity to the desired target. We believe that this additional determinant provides a plausible and simple approach for improving the strand selection, thereby considerably increasing a specificity of target silencing.

Effect of the guide strand 3'-end structure on the gene-silencing potency of asymmetric siRNA.

siRNAs are short dsRNAs that mediate efficient target gene silencing in a sequence-specific manner. We previously developed a novel siRNA structure, called asiRNA (asymmetric siRNA), which alleviates the off-target effects associated with conventional siRNA structures without decreasing target gene silencing potency. In the present study, we explored the effect of the guide strand 3'-end structure on the gene silencing potency of asiRNA. Interestingly, asiRNAs with a 21 nt guide strand solely composed of RNA resulted in gene silencing that was more than 6-fold more efficient compared with the corresponding asiRNA guide strand harbouring a dTdT (deoxythymidine dinucleotide) at its 3'-end. We demonstrated that the molecular basis of potency of the asiRNA with a 21 nt guide strand composed solely of RNA was due to the enhanced formation of the RISC (RNA-induced silencing complex) and increased affinity towards hAgo2 (human Argonaute2). Our observations may assist researchers in designing new asiRNAs with high on-target silencing efficiency with low off-target effects, which is critical for applications in both basic research and therapeutic development.

Impact of GNB3-C825T, ADRB3-Trp64Arg, UCP2-3'UTR 45 bp del/ins, and PPARγ-Pro12Ala polymorphisms on Bofutsushosan response in obese subjects: a randomized, double-blind, placebo-controlled trial.

Obesity is known to be influenced by a number of genes, including the ß3 subunit of G protein (GNB3), ß3-adrenergic receptor (ADRB3), uncoupling protein 2 (UCP2), and peroxisome proliferator activated receptor gamma (PPARγ). The single nucleotide polymorphisms (SNPs) of the above genes, such as GNB3-C825T, ADRB3-Trp64Arg, UCP2-3'UTR 45 bp del/ins, and PPARγ-Pro12Ala, are associated with obesity and body mass index. The present study evaluates the impact of Bofutsushosan, a traditional Eastern Asian herbal medicine with known anti-obesity properties, on obese subjects according to the presence of the above-mentioned SNPs. Upon randomization, the volunteers were allocated to receive Bofutsushosan (n=55) or placebo (n=56) treatments for 8 weeks. Following the treatment schedule, significant reductions in total cholesterol and significant improvement in the Korean version of obesity-related quality of life scale were seen in the Bofutsushosan-treated group, but not in placebo. Bofutsushosan exerted significant anti-obesity effects on a number of parameters in the carriers of the GNB3-825T allele, but only on waist circumference in the GNB3-C/C homozygote. Significant anti-obesity impact of Bofutsushosan was also seen on a number of obesity-indices in both ADRB3-Arg64 carriers and ADRB3-Trp64 homozygotes, as well as in UCP2-D/D carriers, but not in UCP2-D/I+I/I variants. The effect of Bofutsushosan was more pronounced in PPARγ-Pro/Pro genotype compared to PPARγ-Pro/Ala variants. Thus, the results revealed differential responses of the subjects to the anti-obesity effects of Bofutsushosan treatment according to the polymorphism of the vital obesity-related genes. Our study provides new insight into individualized clinical applications of Bofutsushosan for obesity.

Target gene abundance contributes to the efficiency of siRNA-mediated gene silencing.

The gene-silencing activity of a small interfering RNA (siRNA) is determined by various factors. Considering that RNA interference (RNAi) is an unparalleled technology in both basic research and therapeutic applications, thorough understanding of the factors determining RNAi activity is critical. This report presents observations that siRNAs targeting KRT7 show cell-line-dependent activity, which correlates with the expression level of KRT7 mRNA. By modulating the target mRNA level, it was confirmed that highly expressed genes are more susceptible to siRNA-mediated gene silencing. Finally, several genes that show different expression levels in a cell-line dependent manner were tested, which verified the expression-level-dependent siRNA activities. These results strongly suggest that the abundance of target mRNA is a critical factor that determines the efficiency of the siRNA-mediated gene silencing in a given cellular context. This report should provide practical guidelines for designing RNAi experiments and for selecting targetable genes in RNAi therapeutics studies.

Long dsRNA-mediated RNA interference and immunostimulation: a targeted delivery approach using polyethyleneimine based nano-carriers.

RNA oligonucleotides capable of inducing controlled immunostimulation combined with specific oncogene silencing via an RNA interference (RNAi) mechanism provide synergistic inhibition of cancer cell growth. With this concept, we previously designed a potent immunostimulatory long double stranded RNA, referred to as liRNA, capable of executing RNAi mediated specific target gene silencing. In this study, we developed a highly effective liRNA based targeted delivery system to apply in the treatment of glioblastoma multiforme. A stable nanocomplex was fabricated by complexing multimerized liRNA structures with cross-linked branched poly(ethylene imine) (bPEI) via electrostatic interactions. We show clear evidence that the cross-linked bPEI was quite effective in enhancing the cellular uptake of liRNA on U87MG cells. Moreover, the liRNA-PEI nanocomplex provided strong RNAi mediated target gene silencing compared to that of the conventional siRNA-PEI complex. Further, the bPEI modification strategy with specific ligand attachment assisted the uptake of the liRNA-PEI complex on the mouse brain endothelial cell line (b.End3). Such delivery systems combining the beneficial elements of targeted delivery, controlled immunostimulation, and RNAi mediated target silencing have immense potential in anticancer therapy.