Aptamer AS411 interacts with the KRAS promoter/hnRNP A1 complex and shows increased potency against drug-resistant lung cancer.

G-quadruplex (G4) aptamers that can competitively binding protein with oncogene promoter G4 hold promise for cancer treatment. In this study, a neutral cytidinyl lipid, DNCA, was shown to transfect and deliver G4 aptamers (AS1411, TBA) into tumour cells, including multidrug-resistant tumour cells, and their nuclear localizations were clearly detected. Both AS1411/DNCA and TBA/DNCA showed excellent antitumour efficacies in the drug-resistant non-small cell lung cancer cell line A549/TXL at a low concentration (100 nM). Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) was identified as a new target of AS1411 and TBA. The binding affinities were measured, and the Kd values of AS1411/hnRNP A1 and TBA/hnRNP A1 were 17.5 nM and 21.1 nM, respectively. Then the expression of KRAS mRNA in A549/TXL cells was found to be higher than that in A549 cells, and KRAS mRNA was reduced by approximately 40% after administration of AS1411 or TBA in A549/TXL cells. Further, it was confirmed for the first time that AS1411 targeted not only hnRNP A1 but also the KRAS promoter/hnRNP A1 complexes. And although TBA cannot target the KRAS promoter/hnRNP A1 complexes, the biolayer interferometry (BLI) experiment showed that TBA and AS1411 have similar effects on several key proteins in tumour cells, especially hnRNP A1. Molecular docking and molecular dynamics simulation showed that AS1411 and the KRAS promoter bound to the same domain of hnRNP A1 protein, while TBA bound to another domain.

Correction: Aptamer AS1411 interacts with the KRAS promoter/hnRNP A1 complex and shows increased potency against drug-resistant lung cancer.

[This corrects the article DOI: 10.1039/D3MD00752A.].

Impact of Learning Burnout on Mobile Phone Dependence Among Adolescents in Western China Under the "Double Reduction" Policy: The Mediating Role of Social Support.

Purpose: This paper investigated the prevalence of mobile phone dependence (MPD) and its associated with learning burnout under the "double reduction" policy among adolescents in Guizhou Province in western China. In addition, the influence of the mediating mechanism of social support on this relationship was investigated. Methods: The sample was collected from 16,216 adolescents in West China's Guizhou province, from December 2021 to January 2022 via multistage stratified random sampling. The Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use (SQAPMPU) was used to assess the MPD, the Adolescent Student Burnout Scale (ASBI) was used to assess the learning burnout, and the Social Support Scale (SSS) was used to assess the social support. A hierarchical linear regression model was used to analyze the relationship between MPD, learning burnout, and social support. The mediating effect of social support between MPD and learning burnout was analyzed by structural equation model. Results: Prevalence of MPD was 26.4% among adolescents in Guizhou province in western China. After adjusting for confounding variables like demographics, multiple linear regression model has revealed that learning burnout positively predicted MPD and social support negatively predicted MPD. The structural equation model showed that 10.9% of the effect was explained by the mediating effect of social support. Conclusion: These findings could inform service delivery and policy formulation to reduce learning and avoid MPD in adolescents.

Construction of Carbon Nanofiber-Wrapped SnO2 Hollow Nanospheres as Flexible Integrated Anode for Half/Full Li-Ion Batteries.

SnO2 is deemed a potential candidate for high energy density (1494 mAh g-1) anode materials for Li-ion batteries (LIBs). However, its severe volume variation and low intrinsic electrical conductivity result in poor long-term stability and reversibility, limiting the further development of such materials. Therefore, we propose a novel strategy, that is, to prepare SnO2 hollow nanospheres (SnO2-HNPs) by a template method, and then introduce these SnO2-HNPs into one-dimensional (1D) carbon nanofibers (CNFs) uniformly via electrospinning technology. Such a sugar gourd-like construction effectively addresses the limitations of traditional SnO2 during the charging and discharging processes of LIBs. As a result, the optimized product (denoted SnO2-HNP/CNF), a binder-free integrated electrode for half and full LIBs, displays superior electrochemical performance as an anode material, including high reversible capacity (~735.1 mAh g-1 for half LIBs and ~455.3 mAh g-1 at 0.1 A g-1 for full LIBs) and favorable long-term cycling stability. This work confirms that sugar gourd-like SnO2-HNP/CNF flexible integrated electrodes prepared with this novel strategy can effectively improve battery performance, providing infinite possibilities for the design and development of flexible wearable battery equipment.

Effect of birth asphyxia on neonatal blood glucose during the early postnatal life: A multi-center study in Hubei Province, China.

BACKGROUND: Birth asphyxia causes hypoxia or inadequate perfusion to the organs of newborns, leading to metabolism dysfunctions including blood glucose disorders. METHODS: Neonates with and without birth asphyxia were retrospectively recruited from 53 hospitals in Hubei Province from January 1 to December 31, 2018. In summary, 875, 1139, and 180 cases in the control group, the mild asphyxia group, and the severe asphyxia group were recruited, respectively. Neonatal blood glucose values at postnatal 1, 2, 6, and 12 h (time error within 0.5 h was allowed) were gathered from the medical records. RESULTS: The incidence rates of hyperglycemia in the control group, the mild asphyxia group and the severe asphyxia group were 2.97%, 7.90%, and 23.33%, respectively (p < 0.001). Additionally, the incidence rates of hypoglycemia in the three groups above were 3.66%, 4.13%, and 7.78%, respectively (p = 0.042). The blood glucose values of neonates with hypoglycemia in the asphyxia group were lower than in the control group (p = 0.003). Furthermore, the blood glucose values of neonates with hyperglycemia were highest in the severe asphyxia group (p < 0.001). There were 778 and 117 cases with blood glucose records at four predefined time points in the mild and severe asphyxia group, respectively. The incidence of blood glucose disorders in the mild asphyxia group significantly decreased from postnatal 6 h (p＜0.05). However, we found no obvious changes of the incidence of glucose disorders within postnatal 12 h in the severe asphyxia group (p = 0.589). CONCLUSION: Birth asphyxia is likely to cause neonatal blood glucose disorders, both hypoglycemia and hyperglycemia, during the early postnatal life. The neonates with severe asphyxia have higher incidence, worse severity and longer duration of blood glucose disorders than neonates with mild asphyxia.

The relationship between mobile phone dependence and academic burden among junior middle school students in Guizhou Province / 中国学校卫生

Objective@#To explore the relationship between mobile phone dependence (MPD) and academic burden among junior middle school students in Guizhou Province, under the "double reduction" policy by using a multi level model, so as to provide a basis for preventing the occurrence of MPD.@*Methods@#From December 2021 to January 2022, 7 868 students from grade 1 to grade 3 in 3 cities (prefecture) of Guizhou Province were selected by multi stage stratification random sampling method, and on site investigation was conducted by self compiled questionnaire and Self rating Questionnaire for Adolescent Problematic Mobile Phone Use(SQAPMPU). Using MLwiN 2.30 to fit a multi level model of the relationship between MPD and academic burden among junior middle school students.@*Results@#The MPD detection rate of junior middle school students in Guizhou Province was 20.9%. The multi level model revealed that MPD of junior middle school students was clustered at the level of school and class ( χ 2= 1 565.32 , P <0.01), and high perceived academic pressure had a positive predictive effect on MPD among junior middle school students ( β =1.96). Homework duration ≥90 min/d at weekends had a negative predictive effect on MPD ( β =-0.55), while participation in off campus training on learning days had a positive predictive effect ( β =1.66)( P <0.05).@*Conclusion@#The MPD occurrence level is higher among junior middle school students in Guizhou Province. Perceived academic pressure, time spent on homework during weekends, off campus training and other academic burdens have an impact on MPD among junior middle school students, which should be a cause of concern for schools, families and social departments.

d-/l-Isothymidine incorporation in the core sequence of aptamer BC15 enhanced its binding affinity to the hnRNP A1 protein.

The heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) was reported to participate in the development of a variety of tumors. BC15 is a DNA aptamer targeting hnRNP A1. Firstly, through sequence truncation, we identified 31-mer sequence BC15-31 as the core sequence of BC15 with a strong binding affinity and high selectivity to the hnRNP A1 protein. Isothymidine (isoT) modification was then applied for the structural optimization of BC15-31, systematic modification and biological evaluation were carried out. Incorporation of isoT in the 1,3 sites at the 5'-end of BC15-31 can significantly enhance the protein affinity. Chemical modifications close to the 3'-end can greatly improve the stability of the aptamer. Furthermore, BC15-31 modified with isoT at both the 5'-end and 3'-end displayed an additive effect with enhanced bioactivity and stability at the same time. Our study strategy on BC15 provides a useful guideline for chemical modification and optimization of the aptamer for further clinical application.

Annealing novel nucleobase-lipids with oligonucleotides or plasmid DNA based on H-bonding or π-π interaction: Assemblies and transfections.

Lipid derivatives of nucleoside analogs have been highlighted for their potential for effective gene delivery. A novel class of nucleobase-lipids are rationally designed and readily synthesized, comprising thymine/cytosine, an ester/amide linker and an oleyl lipid. The diversity of four nucleobase-lipids termed DXBAs (DOTA, DNTA, DOCA and DNCA) is investigated. Besides, DNCA is demonstrated to be an effective neutral transfection material for nucleic acid delivery, which enbles to bind to oligonucleotides via H-bonding and π-π stacking with reduced toxicity in vitro and in vivo. Several kinds of nucleic acid drugs including aptamer, ssRNA, antisense oligonucleotide, and plasmid DNAs can be delivered by DXBAs, especially DNCA. In particular, G4-aptamer AS1411 encapsulated by DNCA exhibits cellular uptake enhancement, lysosome degradation reduction, cell apoptosis promotion, cell cycle phase alteration in vitro and duration prolongation in vivo, resulting in significant anti-proliferative activity. Our results demonstrate that DNCA is a promising transfection agent for G4-aptamers and exhibites bright application prospects in the permeation improvement of single-stranded oligonucleotides or plasmid DNAs.

The Bioactivity of D-/L-Isonucleoside- and 2'-Deoxyinosine-Incorporated Aptamer AS1411s Including DNA Replication/MicroRNA Expression.

In this study, chemical modification of 2'-deoxyinosine (2'-dI) and D-/L-isothymidine (D-/L-isoT) was performed on AS1411. They could promote the nucleotide-protein interaction by changing the local conformation. Twenty modified sequences were obtained, FCL-I and FCL-II showed the most noticeable activity improvement. They stabilized the G-quadruplex, remained highly resistant to serum degradation and specificity for nucleolin, further inhibited tumor cell growth, exhibited a stronger ability to influence the different phases of the tumor cell cycle, induced S-phase arrest, promoted the inhibition of DNA replication, and suppressed the unwound function of a large T antigen as powerful as AS1411. The microarray analysis and TaqMan PCR results showed that FCL-II can upregulate the expression of four breast-cancer-related, lowly expressed miRNAs and downregulate the expression of three breast-cancer-related, highly expressed miRNAs (>2.5-fold). FCL-II resulted in enhanced treatment effects greater than AS1411 in animal experiments (p < 0.01). The computational results further proved that FCL-II exhibits more structural advantages than AS1411 for binding to the target protein nucleolin, indicating its great potential in antitumor therapy.

Reductive nanocomplex encapsulation of cRGD-siRNA conjugates for enhanced targeting to cancer cells.

In this study, through covalent conjugation and lipid material entrapment, a combined modification strategy was established for effective delivery of small interfering RNA (siRNA). Single strands of siRNA targeting to BRAFV600E gene (siMB3) conjugated with cRGD peptide at 3'-terminus or 5'-terminus via cleavable disulfide bond was synthesized and then annealed with corresponding strands to obtain single and bis-cRGD-siRNA conjugates. A cationic lipid material (CLD) developed by our laboratory was mixed with the conjugates to generate nanocomplexes; their uniformity and electrical property were revealed by particle size and zeta potential measurement. Compared with CLD/siBraf, CLD/cRGD-siBraf achieved higher cell uptake and more excellent tumor-targeting ability, especially 21 (sense-5'/antisense-3″-cRGD-congjugate) nanocomplex. Moreover, they can regulate multiple pathways to varying degree and reduce acidification of endosome. Compared with the gene silencing of different conjugates, single or bis-cRGD-conjugated siRNA showed little differences except 22 (5/5) which cRGD was conjugated at 5'-terminus of antisense strand and sense strand. However bis-cRGD conjugate 21 nanocomplex exhibited better specific target gene silencing at multiple time points. Furthermore, the serum stabilities of the bis-cRGD conjugates were higher than those of the single-cRGD conjugates. In conclusion, all these data suggested that CLD/bis-conjugates, especially CLD/21, can be an effective system for delivery of siRNA to target BRAFV600E gene for therapy of melanoma.

Alkylation of phosphorothioated thrombin binding aptamers improves the selectivity of inhibition of tumor cell proliferation upon anticoagulation.

BACKGROUND: Recently, aptamers have been extensively researched for therapy and diagnostic applications. Thrombin-binding aptamer is a 15nt deoxyribonucleic acid screened by SELEX, it can specifically bind to thrombin and inhibit blood coagulation. Since it is also endowed with excellent antitumor activity, the intrinsic anticoagulation advantage converted to a main potential side effect for its further application in antiproliferative therapy. METHODS: Site-specific alkylation was conducted through nucleophilic reaction of phosphorothioated TBAs using bromide reagents. Circular dichroism (CD) spectroscopy and surface plasmon resonance (SPR) measurements were used to evaluate anticoagulation activity, and a CCK-8 assay was used to determine cell proliferation activity. RESULTS: The CD spectra of the modified TBAs were weakened, and their affinity for thrombin was dramatically reduced, as reflected by the KD values. On the other hand, their inhibition of A549 cells was retained. CONCLUSIONS: Incorporation of different alkyls apparently disrupted the binding of TBA to thrombin while maintaining the antitumor activity. GENERAL SIGNIFICANCE: A new modification strategy was established for the use of TBA as a more selective antitumor agent.

Chemical modification improves the stability of the DNA aptamer GBI-10 and its affinity towards tenascin-C.

Aptamers are useful tools in molecular imaging due to their numerous attractive properties, such as excellent affinity and selectivity to diverse types of target molecules and biocompatibility. We carried out structure-activity relationship studies with the tenascin-C (TN-C) binding aptamer GBI-10, which is a promising candidate in tumor imaging. To increase the tumor targeting ability and nuclease resistance under physiological conditions, systematic modifications of GBI-10 with single and multiple 2'-deoxyinosine (2'-dI) or d-/l-isonucleoside (d-/l-isoNA) were performed. Results indicated that sector 3 of the proposed secondary structure is the most important region for specific binding with TN-C. By correlating the affinity of eighty-four GBI-10 derivatives with their predicted secondary structure by Zuker Mfold, we first validated the preferred secondary structure at 37 °C. We found that d-/l-isoNA modified GBI-10 derivatives exhibited improved affinity to the target as well as plasma stability. Affinity measurement and confocal imaging analysis highlighted one potent compound: 4AL/26TL/32TL, which possessed a significantly increased targeting ability to tumor cells. These results revealed the types of modified nucleotides, and the position and number of substituents in GBI-10 that were critical to the TN-C binding ability. Stabilized TN-C-binding DNA aptamers were prepared and they could be further developed for tumor imaging. Our strategy to introduce 2'-dI and d-/l-isoNA modifications after the selection process is likely to be generally applicable to improve the in vivo stability of aptamers without compromising their binding ability.

Circulating microRNAs as biomarkers for the early diagnosis of childhood tuberculosis infection.

MicroRNAs (miRNAs) are a class of highly conserved, single-stranded RNA molecules (length, 18-25 nt) that regulate the expression of their target mRNAs. Previous studies have demonstrated that miRNAs may be novel biomarkers in the diagnosis of certain diseases. In order to evaluate the diagnostic value of miRNAs in childhood tuberculosis (TB), the circulating miRNA profile was determined using microarray analysis. An miRNA­gene network was constructed to identify closely associated miRNAs and these miRNAs were validated using reverse transcription­quantitative polymerase chain reaction (RT­qPCR). A receiver operational curve (ROC) was used to evaluate the diagnostic sensitivity and specificity of confirmed miRNAs. The microarray data demonstrated that 29 miRNAs were altered with 15 upregulated and 14 downregulated. The network showed indicated 14 miRNAs that are critical in childhood TB. RT-qPCR validated that miR-1, miR-155, miR­31, miR­146a, miR­10a, miR­125b and miR­150 were downregulated in while miR­29 was upregulated in children with TB compared with uninfected children. The ROC curve data indicated the diagnostic value of single miRNA was as follows: miR­150>miR­146a>miR­125b>miR­31>miR­10a>miR­1>miR­155>miR­29. Notably, a combination of these miRNAs exhibited increased diagnostic value compared with any single miRNA. To the best of our knowledge, the present study is the first to identify the expression profile of circulating miRNAs in childhood TB and demonstrated that miRNAs may be a novel, non­invasive and effective biomarker for the early diagnosis of childhood TB.

Spatial conservation studies of nucleobases in 10-23 DNAzyme by 2'-positioned isonucleotides and enantiomers for increased activity.

2'-Positioned isonucleotides and enantiomers were used to evaluate the conservation of the spatial location of five adenines and two thymines in the catalytic core of 10-23 DNAzyme. The positive effect of isonucleotides at A15 and T8 along with inherent enzymatic resistance could be a tangible solution for the practical applications of 10-23 DNAzyme.

Stability and bioactivity of thrombin binding aptamers modified with D-/L-isothymidine in the loop regions.

Thrombin binding aptamer (TBA) is a 15-mer single-strand DNA that was identified by SELEX screening technology. It adopts a chair-type antiparallel G-quadruplex and can specifically interact with thrombin, thus inhibiting blood coagulation. Isonucleoside (isoNA) is a type of nucleoside isomer in which the base is shifted to 2'-positions of the glycosyl group, endowed with the ability to modulate local conformation of nucleotides, and L-isoNA could alter the conformation more due to the inversion of glycosyl configuration. Incorporation of L-isothymidine (L-isoT) at T3, T9, T12 positions and D-isoT at the T7 position in TBA's loop regions promoted the formation of G-quadruplex, resulting in enhanced affinity with thrombin and an increased anticoagulant effect. Computer simulation indicated that TBA-12L showed the strongest binding with thrombin, which was consistent with experimental results. The bioactivity of double isoNA incorporated TBA with D-IsoT at T7 and L-IsoT at T12 was comparable to that of TBA-12L, suggesting that the T12 of TBA was very important in interaction with thrombin. Our study also suggested that TBA might interact with two thrombin molecules through the TT loops (T3T4, T12T13) and TGT loop, but the second bonding did not show additional biological effects.