Hypoxia Inhibitor Combined with Chemotherapeutic Agents for Antitumor and Antimetastatic Efficacy against Osteosarcoma.

Chemotherapy is the main treatment method for osteosarcoma in the clinic. However, drug resistance and its poor antimetastatic effects greatly limit its clinical application. In this work, dual-drug nanoparticles (NPs) containing albendazole (ABZ) and doxorubicin (DOX), named AD@PLGA-PEG NPs, were prepared to solve the problems of chemotherapeutic drug resistance and poor antimetastasis effects. Compared with free DOX, ABZ combined with DOX can increase intracellular reactive oxygen species (ROS) and induce more tumor cell apoptosis; therefore, AD@PLGA-PEG NPs produced more mitochondria-mediated oxidative stress and better apoptosis efficiency. Importantly, ABZ can also effectively inhibit the expression of hypoxia inducible factor-1α (HIF-1α) and then reduce the expression of its downstream vascular endothelial growth factor (VEGF); thus, the AD@PLGA-PEG NPs effectively inhibited tumor metastasis in vivo. Collectively, the dual-drug AD@PLGA-PEG NPs delivery system provided prominent antitumor and antimetastatic efficacy and might be a promising treatment for osteosarcoma.

Effects of obstructive sleep apnea during rapid eye movement sleep on cardiac autonomic dysfunction: Results from the Shanghai sleep health study cohort.

In our large-scale study, the correlation between obstructive sleep apnea (OSA) related to rapid eye movement (REM) sleep and cardiac autonomic dysfunction was assessed by standard polysomnography (PSG). Cardiac autonomic dysfunction was evaluated by the measurement of heart rate variability (HRV). The cardiovascular disease (CVD) risk was determined using the cross-sectional prevalence of CVD and its overall 10 year risk according to the Framingham risk score (FRS). 4152 individuals were included in the study. A higher apnea-hypopnea index during REM sleep (AHIREM ) was correlated with increased CVD risk. The adjusted odds ratios (95% CIs) for CVD prevalence and its high 10 year risk in participants having severe OSA during REM sleep (AHIREM ≥30 events/h) were 1.452 (1.012-2.084) and 1.904 (1.470-2.466) in the demographic adjusted model and 1.175 (0.810-1.704) and 1.716 (1.213-2.427) in the multivariate adjusted model, respectively, compared with the group with a AHIREM of <5 events/h. Fully adjusted multivariate linear regression models showed the independent association between AHIREM and a more elevated ratio of low-frequency and high-frequency (LF/HF) and LF in normalised units [LF (n.u.)] (P = 0.042, P = 0.027 in all participants and P = 0.033, P = 0.029 in participants with AHI during non-REM sleep <5 events/h, respectively). Mediation analysis demonstrated that OSA during REM sleep and CVD risk was significantly mediated by LF/HF and LF (n.u.). OSA during REM sleep may be a marker behind CVD risk because it promotes cardiac autonomic dysfunction.

Synergistic Platinum(II) Prodrug Nanoparticles for Enhanced Breast Cancer Therapy.

Chemotherapy still accounts for a large proportion of the treatments of tumors, but the drug resistance and side effects caused by long-term chemotherapy should not be underestimated. In this work, the drug combination strategy has been widely developed to overcome the side effects brought by the use of single drugs and improve the therapeutic effect. However, in clinical applications, the co-delivery of drugs is very difficult, and different in vivo kinetics due to different drug properties will lead to a decrease in efficacy. Thus, the design of novel antitumor therapeutic agents, including new platinum agents, represents an area in need of urgent attention. Our investigation implies a promising strategy for the design of a platinum prodrug to enhance the treatment of breast cancer. A dual-drug delivery nanoparticle was developed for enhanced treatment of breast cancer based on a two-into-one co-delivery strategy. Through the synergistic effect of released cisplatin hydrate and tolfenamic acid (COX-2 inhibitor) from the coordination prodrug, the tumor growth is significantly suppressed, and the survival time is greatly extended in breast tumor-bearing mice.

The SAUR41 subfamily of SMALL AUXIN UP RNA genes is abscisic acid inducible to modulate cell expansion and salt tolerance in Arabidopsis thaliana seedlings.

BACKGROUND AND AIMS: Most primary auxin response genes are classified into three families: AUX/IAA, GH3 and SAUR genes. Few studies have been conducted on Arabidopsis thaliana SAUR genes, possibly due to genetic redundancy among different subfamily members. Data mining on arabidopsis transcriptional profiles indicates that the SAUR41 subfamily members of SMALL AUXIN UP RNA genes are, strikingly, induced by an inhibitory phytohormone, abscisic acid (ABA). We aimed to reveal the physiological roles of arabidopsis SAUR41 subfamily genes containing SAUR40, SAUR41, SAUR71 and SAUR72. METHODS: Transcriptional responses of arabidopsis SAUR41 genes to phytohormones were determined by quantitative real-time PCR. Knock out of SAUR41 genes was carried out with the CRISPR/Cas9 (clustered regulatory interspaced short palindromic repeats/CRISPR-associated protein 9) genome editing technique. The saur41/40/71/72 quadruple mutants, SAUR41 overexpression lines and the wild type were subjected to ultrastructural observation, transcriptome analysis and physiological characterization. KEY RESULTS: Transcription of arabidopsis SAUR41 subfamily genes is activated by ABA but not by gibberellic acids and brassinosteroids. Quadruple mutations in saur41/40/71/72 led to reduced cell expansion/elongation in cotyledons and hypocotyls, opposite to the overexpression of SAUR41; however, an irregular arrangement of cell size and shape was observed in both cases. The quadruple mutants had increased transcription of calcium homeostasis/signalling genes in seedling shoots, and the SAUR41 overexpression lines had decreased transcription of iron homeostasis genes in roots and increased ABA biosynthesis in shoots. Notably, both the quadruple mutants and the SAUR41 overexpression lines were hypersensitive to salt stress during seedling establishment, whereas specific expression of SAUR41 under the ABA-responsive RD29A (Responsive to Desiccation 29A) promoter in the quadruple mutants rescued the inhibitory effect of salt stress. CONCLUSIONS: The SAUR41 subfamily genes of arabidopsis are ABA inducible to modulate cell expansion, ion homeostasis and salt tolerance. Our work may provide new candidate genes for improvement of plant abiotic stress tolerance.

Gold nanoparticle-based colorimetric ELISA for quantification of ractopamine.

The work describes a gold nanoparticle-based colorimetric enzyme-linked immunosorbent assay (ELISA) for ractopamine. The ELISA is based on an indirect competitive approach. In the presence of ractopamine, gold(III) ions are oxidized by H2O2 to form red AuNPs. On the other hand, the AuNP in solution are purple-blue due to aggregation if the sample does not contain ractopamine. The absorption, best measured at 560 nm, increases linearly in the 2 to 512 ng·mL-1 ractopamine concentration range, and the detection limit is as low as 0.35 ng·mL-1 in urine. Ractopamine can also be detected visually, even in the presence of other ß-agonists and antibiotics. The results obtained by this method are consistent with those obtained by LC-MS/MS as demonstrated by analysis of sheep urine. The ELISA method described here is inexpensive, easy-to-use, and suitable for rapid screening of ractopamine in animal samples. Graphical abstract Schematic presentation of a colorimetric indirect competitive immunoassay for ractopamine. It is based on the use of catalase labeled IgG and the measurement of the absorption of red gold nanoparticles (AuNPs) that are generated by the reaction of gold ions with H2O2. In the absence of ractopamine, the solution becomes blue.

Quantification of Gly m 5.0101 in Soybean and Soy Products by Liquid Chromatography-Tandem Mass Spectrometry.

Gly m 5.0101, the alpha subunit of ß-conglycinin, is one of the major allergens found in soybeans that has been identified as causing an allergic reaction. Here, we developed a quantification method of Gly m 5.0101 with multiple reaction monitoring using the synthetic peptide 194NPFLFGSNR202 as the external standard. Firstly, the ground soybean was defatted and extracted with a protein extraction buffer. Then the crude extract was on-filter digested by trypsin and analyzed by liquid chromatography-tandem mass spectrometry. The selected peptide exhibited a detection limit of 0.48 ng/mL and a linear relationship in a concentration range from 1.6 to 500 ng/mL (r² > 0.99). The developed method was successfully applied to quantify the Gly m 5.0101 level in dozens of soybean varieties from different sources and soybean products derived from different processing techniques. The developed method could be used to further analyze ß-conglycinin in soybean seeds combined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis.

Chemical Modification of Chitosan for Efficient Vaccine Delivery.

Chitosan, which exhibits good biocompatibility, safety, microbial degradation and other excellent performances, has found application in all walks of life. In the field of medicine, usage of chitosan for the delivery of vaccine is favored by a wide range of researchers. However, due to its own natural limitations, its application has been constrained to the beginning of study. In order to improve the applicability for vaccine delivery, researchers have carried out various chemical modifications of chitosan. This review summarizes a variety of modification methods and applications of chitosan and its derivatives in the field of vaccine delivery.

A rapid Salmonella detection method involving thermophilic helicase-dependent amplification and a lateral flow assay.

Salmonella is a major foodborne pathogen that is widespread in the environment and can cause serious human and animal disease. Since conventional culture methods to detect Salmonella are time-consuming and laborious, rapid and accurate techniques to detect this pathogen are critically important for food safety and diagnosing foodborne illness. In this study, we developed a rapid, simple and portable Salmonella detection strategy that combines thermophilic helicase-dependent amplification (tHDA) with a lateral flow assay to provide a detection result based on visual signals within 90 min. Performance analyses indicated that the method had detection limits for DNA and pure cultured bacteria of 73.4-80.7 fg and 35-40 CFU, respectively. Specificity analyses showed no cross reactions with Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Enterobacter aerogenes, Shigella and Campylobacter jejuni. The results for detection in real food samples showed that 1.3-1.9 CFU/g or 1.3-1.9 CFU/mL of Salmonella in contaminated chicken products and infant nutritional cereal could be detected after 2 h of enrichment. The same amount of Salmonella in contaminated milk could be detected after 4 h of enrichment. This tHDA-strip can be used for the rapid detection of Salmonella in food samples and is particularly suitable for use in areas with limited equipment.

L-Glutamine deprivation induces autophagy and alters the mTOR and MAPK signaling pathways in porcine intestinal epithelial cells.

L-Glutamine (Gln) is an essential amino acid for intestinal growth and integrity. However, the underlying molecular mechanisms are not fully known. In the present study, porcine intestinal epithelial cells (IPEC-1) were used to test the hypothesis that autophagy is induced by Gln deprivation and inhibited by Gln supplementation. After a 2-day period of growth in normal medium, IPEC-1 cells were transferred to a Gln-free custom-made DMEM. Cell numbers, the distribution of autophagosomes, the abundance of the protein for an autophagy marker LC3B, as well as abundances of the mTOR and MAPK proteins during an 8-h period were determined. Furthermore, the rescue effect of 5 mM Gln was evaluated. Our results showed that Gln deprivation reduced the cell number, while enhancing the accumulation of autophagosomes and the expression of LC3B-II in IPEC-1 cells within 8 h. The concentrations of Glu, Asp, Cit, Arg, Leu, Ile, Val, Ala, ß-Ala, Orn, Phe, Met and Ser in the culture medium were altered by Gln deprivation. Further analysis revealed that Gln deficiency inactivated, but Gln supplementation activated, the mTOR and MAPK/ERK signaling pathways. Collectively, our findings support the notion that Gln deficiency induces autophagy and disturbs amino acid metabolism in intestinal epithelial cells, as well as attenuated their mTOR and MAPK/ERK signaling pathways to inhibit protein synthesis and cell proliferation.

Emerging roles of circular RNAs in regulating the hallmarks of thyroid cancer.

Thyroid cancer is a prevalent endocrine malignancy with increasing incidence in recent years. Although most thyroid cancers grow slowly, they can become refractory, leading to a high mortality rate once they exhibit recurrence, metastasis, resistance to radioiodine therapy, or a lack of differentiation. However, the mechanisms underlying these malignant characteristics remain unclear. Circular RNAs, a type of closed-loop non-coding RNAs, play multiple roles in cancer. Several studies have demonstrated that circular RNAs significantly influence the development of thyroid cancers. In this review, we summarize the circular RNAs identified in thyroid cancers over the past decade according to the hallmarks of cancer. We found that eight of the 14 hallmarks of thyroid cancers are regulated by circular RNAs, whereas the other six have not been reported to be correlated with circular RNAs. This review is expected to help us better understand the roles of circular RNAs in thyroid cancers and accelerate research on the mechanisms and cure strategies for thyroid cancers.

Differences in Physiologic Endotypes Between Nonpositional and Positional OSA: Results From the Shanghai Sleep Health Study Cohort.

BACKGROUND: Positional OSA (POSA) is a recognized subtype of OSA that exhibits distinct endotypic characteristics when compared with nonpositional OSA (NPOSA). The basis for the disparity in endotypes between these subtypes remains poorly understood. RESEARCH QUESTION: (1) Do individuals with NPOSA and POSA have different underlying OSA endotypes? (2) Which endotypic characteristics are critical in determining NPOSA and POSA severity? STUDY DESIGN AND METHODS: Within the Shanghai Sleep Health Study cohort, individuals with OSA were recruited and classified as having POSA or NPOSA. Endotypes were calculated using polysomnography. RESULTS: Endotype analysis was conducted in 1,036 individuals with OSA. Compared with individuals with NPOSA, those with POSA had lower loop gain calculated during all sleep stages and all sleep positions (0.55; interquartile range [IQR], 0.46-0.66 vs 0.68, IQR, 0.52-0.90; P < .001), lower arousal threshold calculated during all sleep stages and all sleep positions (ArTHAll) (138.67; IQR, 118.94-180.87 percentage of the eupneic ventilation [%Veupnea] vs 189.00; IQR, 129.71-257.76 %Veupnea; P < .001), lower pharyngeal collapsibility calculated during all sleep stages and all sleep positions (VpassiveAll) (91.85; IQR, 83.13-95.15 %Veupnea vs 76.38; IQR, 23.77-92.08 %Veupnea; P < .001), and higher muscle compensation calculated during all sleep stages and all sleep positions (6.50; IQR, -6.77 to 16.39 %Veupnea vs 3.65; IQR, -10.47 to 12.14 %Veupnea; P = .003). Logistic regression analyses indicated that higher VpassiveAll was associated with increased odds of POSA vs NPOSA. In NPOSA, fully adjusted linear regression analyses indicated that VpassiveAll (ß = -0.55; 95% CI, -0.68 to -0.42; P < .001) and lower loop gain calculated during all sleep stages and all sleep positions (ß = 0.19; 95% CI, 0.08-0.30; P < .001) were significant independent predictors of the apnea hypopnea index, with VpassiveAll being the most critical factor. In contrast, in POSA, collapsibility appeared to be less influential (ß = -0.09; 95% CI, -0.21 to 0.03; P = .138). Nonanatomic endotypic characteristics (LGAll: ß = 0.29; 95% CI, 0.18-0.41; P < .001; arousal threshold in all sleep stages and all sleep positions: ß = 0.15; 95% CI, 0.01-0.28; P = .031; muscle compensation in all sleep stages and all sleep positions: ß = -0.21; 95% CI, -0.29 to -0.12; P < .001) were significant in determining the severity of POSA, with loop gain being the most crucial factor. INTERPRETATION: This study highlights the differences in endotypes between NPOSA and POSA. In Chinese individuals, anatomic factors were more significant in determining the severity of NPOSA, whereas nonanatomic traits were more likely to determine the severity of POSA. Future research should focus on developing personalized management strategies for individuals with NPOSA and POSA based on their endotypes. TRIAL REGISTRATION: Chinese Clinical Trial Registry; No.: ChiCTR1900025714; URL: https://www.chictr.org.cn/indexEN.html.

Glutathione depletion and dihydroorotate dehydrogenase inhibition actuated ferroptosis-augment to surmount triple-negative breast cancer.

Ferroptosis is a promising therapeutic approach for combating malignant cancers, but its effectiveness is limited in clinical due to the adaptability and self-repair abilities of cancer cells. Mitochondria, as the pivotal player in ferroptosis, exhibit tremendous therapeutic potential by targeting the intramitochondrial anti-ferroptotic pathway mediated by dihydroorotate dehydrogenase (DHODH). In this study, an albumin-based nanomedicine was developed to induce augmented ferroptosis in triple-negative breast cancer (TNBC) by depleting glutathione (GSH) and inhibiting DHODH activity. The nanomedicine (ATO/SRF@BSA) was developed by loading sorafenib (SRF) and atovaquone (ATO) into bovine serum albumin (BSA). SRF is an FDA-approved ferroptosis inducer and ATO is the only drug used in clinical that targets mitochondria. By combining the effects of SRF and ATO, ATO/SRF@BSA promoted the accumulation of lipid peroxides within mitochondria by inhibiting the glutathione peroxidase 4 (GPX4)-GSH pathway and downregulating the DHODH-coenzyme Q (CoQH2) defense mechanism, triggers a burst of lipid peroxides. Simultaneously, ATO/SRF@BSA suppressed cancer cell self-repair and enhanced cell death by inhibiting the synthesis of adenosine triphosphate (ATP) and pyrimidine nucleotides. Furthermore, the anti-cancer results showed that ATO/SRF@BSA exhibited tumor-specific killing efficacy, significantly improved the tumor hypoxic microenvironment, and lessened the toxic side effects of SRF. This work presents an efficient and easily achievable strategy for TNBC treatment, which may hold promise for clinical applications.

Association between multiple sleep dimensions in obstructive sleep apnea and an early sign of atherosclerosis.

STUDY OBJECTIVES: We investigated the associations between multiple sleep dimensions in obstructive sleep apnea (OSA) and carotid intima-media thickness (CIMT), an early sign of atherosclerosis, in participants from the Shanghai Sleep Health Study. METHODS: We performed secondary analysis of SSHS in a group of subjects who underwent ultrasound evaluation from 2018 to 2022. Multiple sleep dimensions were measured using standard polysomnography. CIMT was measured from ultrasound images as an early sign of atherosclerosis. Multivariable-adjusted linear regression and logistic regression analyses were performed to detect associations between sleep traits in OSA and CIMT. RESULTS: CIMT was found to increase with increasing severity of OSA (P < .001). When adjusted for conventional risk factors, microarousal index and hypoxic burden were positively correlated with CIMT, while slow-wave sleep and mean apnea-hypopnea event duration showed a negative correlation with CIMT (all P < .01). In binary logistic regression analysis, participants with a high microarousal index, less slow-wave sleep, higher hypoxic burden, and shorter mean apnea-hypopnea event duration showed a higher prevalence of thick CIMT with no evidence of interaction by age, sex, or body mass index (P-interaction > .05). CONCLUSIONS: Patients with more severe sleep fragmentation, more severe hypoxemia, and increased arousability were more likely to have increased CIMT after adjusting for potential confounders. It is important to evaluate novel indices of sleep fragmentation, hypoxemia, and arousability in OSA for early detection and prevention of cardiovascular disease, including stroke. CLINICAL TRIAL REGISTRATION: Registry: Chinese Clinical Trial Registry; Name: Establishing Bio-bank and Cohort of OSAHS in Hospital-based Population; URL: http://www.chictr.org.cn/showproj.aspx?proj=43057; Identifier: ChiCTR1900025714. CITATION: Huang W, Zhou E, Zhang J, et al. Association between multiple sleep dimensions in obstructive sleep apnea and an early sign of atherosclerosis. J Clin Sleep Med. 2024;20(7):1093-1104.

Vicious Cycle-Breaking Lipid Nanoparticles Remodeling Multicellular Crosstalk to Reverse Liver Fibrosis.

During liver fibrogenesis, the reciprocal crosstalk among capillarized liver sinusoidal endothelial cells (LSECs), activated hepatic stellate cells (HSCs), and dysfunctional hepatocytes constructs a self-amplifying vicious cycle, greatly exacerbating the disease condition and weakening therapeutic effect. Limited by the malignant cellular interactions, the previous single-cell centric treatment approaches show unsatisfactory efficacy and fail to meet clinical demand. Herein, a vicious cycle-breaking strategy is proposed to target and repair pathological cells separately to terminate the malignant progression of liver fibrosis. Chondroitin sulfate-modified and vismodegib-loaded nanoparticles (CS-NPs/VDG) are designed to efficiently normalize the fenestrae phenotype of LSECs and restore HSCs to quiescent state by inhibiting Hedgehog signaling pathway. In addition, glycyrrhetinic acid-modified and silybin-loaded nanoparticles (GA-NPs/SIB) are prepared to restore hepatocytes function by relieving oxidative stress. The results show successful interruption of vicious cycle as well as distinct fibrosis resolution in two animal models through multiregulation of the pathological cells. This work not only highlights the significance of modulating cellular crosstalk but also provides a promising avenue for developing antifibrotic regimens.

Engineered stem cell-based strategy: A new paradigm of next-generation stem cell product in regenerative medicine.

Stem cells have garnered significant attention in regenerative medicine owing to their abilities of multi-directional differentiation and self-renewal. Despite these encouraging results, the market for stem cell products yields limited, which is largely due to the challenges faced to the safety and viability of stem cells in vivo. Besides, the fate of cells re-infusion into the body unknown is also a major obstacle to stem cell therapy. Actually, both the functional protection and the fate tracking of stem cells are essential in tissue homeostasis, repair, and regeneration. Recent studies have utilized cell engineering techniques to modify stem cells for enhancing their treatment efficiency or imparting them with novel biological capabilities, in which advances demonstrate the immense potential of engineered cell therapy. In this review, we proposed that the "engineered stem cells" are expected to represent the next generation of stem cell therapies and reviewed recent progress in this area. We also discussed potential applications of engineered stem cells and highlighted the most common challenges that must be addressed. Overall, this review has important guiding significance for the future design of new paradigms of stem cell products to improve their therapeutic efficacy.

Global burden of head and neck cancers from 1990 to 2019.

Head and neck cancer (HNC) exerts a significant healthcare burden worldwide. Insufficient data impedes a comprehensive understanding of its global impact. Through analysis of the 2019 Global Burden of Disease (GBD) database, our secondary investigation unveiled a surging global incidence of HNC, yet a decline in associated mortality and disability-adjusted life years (DALYs) owing to enhanced prognosis. Particularly noteworthy is the higher incidence of escalation among females compared to males. Effective resource allocation, meticulous control of risk factors, and tailored interventions are imperative to curtail mortality rates among young individuals afflicted with HNC in underprivileged regions, as well as in elderly individuals grappling with thyroid cancer.

Association between TSH suppression therapy and type 2 deiodinase gene polymorphism in differentiated thyroid carcinoma.

INTRODUCTION: Oral levothyroxine (L-T4) suppression of thyroid-stimulating hormone (TSH) levels is the most commonly used clinical approach to manage and treat patients after thyroid cancer surgery. This study aimed to investigate the association between TSH suppression therapy and type 2 deiodinase gene (DIO2) polymorphism in differentiated thyroid carcinoma (DTC). MATERIAL AND METHODS: A total of 240 patients with DTC who received total thyroidectomy (TT; 120) and hemithyroidectomy (HT; 120) were enrolled in this study. The serum TSH, free triiodothyronine (FT3), and free thyroxine (FT4) levels were detected using an automatic serum immune analyser and electrochemiluminescence immunoassay. Based on the results of DIO2 gene detection, 3 genotypes of Thr92Ala were detected. RESULTS: The serum TSH levels were inhibited after oral L-T4 treatment, but the proportion of patients who reached the TSH suppression standard in the hemithyroidectomy group was higher than in the total thyroidectomy group. After TSH suppression treatment, serum FT4 levels were increased in both total thyroidectomy and hemithyroidectomy. The difference in serum TSH, FT3, and FT4 levels was associated with different genotypes, and patients with high cytosine cytosine (CC) genotypes may have difficulty meeting the TSH suppression criteria. CONCLUSIONS: Patients who underwent total thyroidectomy exhibited higher postoperative serum FT4 levels than patients in the hemithyroidectomy group after TSH suppression therapy. The Thr92Ala polymorphism of type 2 deiodinase (D2) was associated with TSH suppression therapy.

COL, a pipeline for identifying putatively functional back-splicing.

Circular RNAs (circRNAs) are a class of generally non-coding RNAs produced by back-splicing. Although the vast majority of circRNAs are likely to be products of splicing error and thereby confer no benefits to organisms, a small number of circRNAs have been found to be functional. Identifying other functional circRNAs from the sea of mostly non-functional circRNAs is an important but difficult task. Because available experimental methods for this purpose are of low throughput or versality and existing computational methods have limited reliability or applicability, new methods are needed. We hypothesize that functional back-splicing events that generate functional circRNAs (i) exhibit substantially higher back-splicing rates than expected from the total splicing amounts, (ii) have conserved splicing motifs, and (iii) show unusually high back-splicing levels. We confirm these features in back-splicing shared among human, macaque, and mouse, which should enrich functional back-splicing. Integrating the three features, we design a computational pipeline named COL for identifying putatively functional back-splicing. Using experimentally verified functional back-splicing as a benchmark, we find COL to outperform a commonly used computational method with a similar data requirement. We conclude that COL is an efficient and versatile method for rapid identification of putatively functional back-splicing and circRNAs that can be experimentally validated.

Tumor microenvironment-initiated lipid redox cycling for efficient triple-negative breast cancer therapy.

The use of overwhelming reactive oxygen species (ROS) attack has shown great potential for treating aggressive malignancies; however, targeting this process for further applications is greatly hindered by inefficiency and low selectivity. Here, a novel strategy for ROS explosion induced by tumor microenvironment-initiated lipid redox cycling was proposed, which was developed by using soybean phosphatidylcholine (SPC) to encapsulate lactate oxidase (LOX) and sorafenib (SRF) self-assembled nanoparticles (NPs), named LOX/SRF@Lip. SPC is not only the delivery carrier but an unsaturated lipid supplement for ROS explosion. And LOX catalyzes excessive intratumoral lactate to promote the accumulation of large amounts of H2O2. Then, H2O2 reacts with excessive endogenous iron ions to generate amounts of hydroxyl radical for the initiation of SPC peroxidation. Once started, the reaction will proceed via propagation to form new lipid peroxides (LPO), resulting to devastating LPO explosion and widespread oxidative damage in tumor cells. Furthermore, SRF makes contribution to mass LPO accumulation by inhibiting LPO elimination. Compared to normal tissue, tumor tissue has higher levels of lactate and iron ions. Therefore, LOX/SRF@Lip shows low toxicity in normal tissues, but generates efficient inhibition on tumor proliferation and metastasis, enabling excellent and safe tumor-specific therapy. This work offers new ideas on how to magnify anticancer effect of ROS through rational nanosystem design and tumor-specific microenvironment utilization.

Injectable rhein-assisted crosslinked hydrogel for efficient local osteosarcoma chemotherapy.

Osteosarcoma (OS) is the most common malignant tumor of the bone that affects children and adolescents, and its treatment usually involves doxorubicin hydrochloride (DOX). However, the drug resistance and side effects caused by high-dose DOX infusion greatly hinder its therapeutic effects. To achieve efficient OS treatment with low toxicity, an injectable rhein (RH)-assisted crosslinked hydrogel (PVA@RH@DOX hydrogel, PRDH) was designed, which was prepared by loading DOX and RH into a polyvinyl alcohol (PVA) solution. The cytotoxicity assay and live/dead staining results showed that the combination of RH and DOX more effectively killed OS cells, producing excellent effects at low concentrations of DOX. The wound healing and transwell test results proved that PRDH could significantly inhibit the metastasis and invasion of OS cells. PRDH showed a long-lasting antitumor effect after injection of a single dose, significantly suppressing the proliferation and metastasis of OS and achieving the strategy of a single administration for long-term treatment. Excitingly, RH facilitated hydrogel formation by assisting with PVA crosslinking. This system provides an alternative regimen and broadens the horizon for the clinical treatment of OS.