Closed Cyclic DNA Machine for Sensitive Logic Operation and APE1 Detection.

DNA self-assembly has been developed as a kind of robust signal amplification strategy, but most of reported assembly pathways are programmed to amplify signal in one direction. Herein, based on mutual-activated cascade cycle of hybridization chain reaction (HCR) and catalytic hairpin assembly (CHA), a closed cycle circuit (CCC) based DNA machine is developed for sensitive logic operation and molecular recognition. Benefiting from the synergistically accelerated signal amplification, the closed cyclic DNA machine enabled the logic computing with strong and significant output signals even at weak input signals. The typical logic operations such as OR, YES, AND, INHIBIT, NOR, and NAND gate, are conveniently and clearly executed with this DNA machine through rational design of the input and computing elements. Moreover, by integrating the target recognition module with the CCC module, the proposed DNA machine is further employed in the homogeneous detection of apurinic/apyrimidinic endonuclease 1 (APE1). The precise recognition and exponential signal amplification facilitated the highly selective and sensitive detection of APE1 with limit of detection (LOD) of 7.8 × 10-5 U mL-1 . Besides, the normal cells and tumor cells are distinguished unambiguously by this method according to the detected concentration difference of cellular APE1, which indicates the robustness and practicability of this method.

A Single-Arm Phase II Study of Nab-Paclitaxel Plus Gemcitabine and Cisplatin for Locally Advanced or Metastatic Biliary Tract Cancer.

PURPOSE: Patients with advanced biliary tract cancer (BTC) have a poor survival. We aim to evaluate the efficacy and safety of nab-paclitaxel plus gemcitabine and cisplatin regimen in Chinese advanced BTC patients. MATERIALS AND METHODS: Eligible patients with locally advanced or metastatic BTC administrated intravenous 100 mg/m2 nab-paclitaxel, 800 mg/m2 gemcitabine, and 25 mg/m2 cisplatin every 3 weeks. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS) and adverse events, while exploratory endpoint was the association of biomarkers with efficacy. RESULTS: After the median follow-up of 25.0 months, the median PFS and OS of 34 enrolled patients were 7.1 months (95% confidence interval [CI], 5.4 to 13.7) and 16.4 months (95% CI, 10.9 to 23.6), respectively. The most common treatment-related adverse events at ≥ 3 grade were neutropenia (26.5%) and leukopenia (26.5%). Survival analyses demonstrated that carcinoembryonic antigen (CEA) levels could monitor patients' survival outcomes. A significant increase in the number of infiltrating CD4+ cells (p=0.008) and a decrease in programmed death-1-positive (PD-1+) cells (p=0.032) were observed in the response patients. CONCLUSION: In advanced BTC patients, nab-paclitaxel plus gemcitabine and cisplatin regimen showed therapeutic potential. Potential prognostic factors of CEA levels, number of CD4+ cells and PD-1+ cells may help us maximize the efficacy benefit.

Label-free and low-background FEN1 sensing based on cleavage-induced ligation of bifunctional dumbbell DNA and in-situ signal readout.

Flap endonuclease 1 (FEN1) is overexpressed in various types of human tumor cells and has been recognized as a promising biomarker for cancer diagnosis in recent years. In this work, a label-free fluorescent nanosensor for FEN1 detection was developed based on cleavage-induced ligation of bifunctional dumbbell DNA and in-situ signal readout by copper nanoparticles (CuNPs). The dumbbell DNA was rationally designed with a FEN1 cleavable 5' flap for target recognition and AT-riched stem-loop template for CuNPs formation. In the presence of FEN1, 5' overhanging DNA flap of dumbbell DNA was effectively removed to form a linkable nick site. After the ligation by T4 DNA ligase, the dumbbell DNA changed to exonuclease-resisted closed structure which enabled in-situ generation of fluorescent CuNPs that served as signal source for target quantification. The low background attributed to synergic digestion by exonucleases facilitated the highly sensitive detection of FEN1 with limit of detection of 0.007 U/mL. Additionally, the sensor was extended to the assay of FEN1 inhibitor (aurintricarboxylic acid) with reasonable results. Last but not least, the normal cells and tumor cells were distinguished unambiguously by this sensor according to the detected concentration difference of cellular FEN1, which indicates the robustness and practicability of this nanosensor.

Highly Stable Fluorescent-Traffic-Light Sensor for Point-of-Care Detection of Tetracycline.

Fluorescent point-of-care (POC) sensors have found great utility in fields like clinical diagnosis, food testing, and environmental monitoring. Herein, we developed a highly stable POC sensor that enabled the visual detection of tetracycline (TC) in a distinct fluorescent-traffic-light manner. In the sensor, a composite material of copper nanoclusters and metal-organic framework (CuNCs@MOF-5) prepared with a facile one-pot synthetic strategy was employed as the core element for target recognition and signal transduction. As evidenced by experiments, the as-prepared CuNCs@MOF-5 exhibited significantly improved fluorescence properties in terms of emission enhancement (about 28-fold) and stability improvement (over 110 days) compared to the CuNCs without confining and protection by MOF-5. More importantly, it was found that TC could uniquely interact with Zn(II) to trigger the disassembly of CuNCs@MOF-5, resulting in green fluorescence emission from the TC-Zn(II) complex and red fluorescence weakening of CuNCs. On the basis of this finding, a simple and stable sensor was proposed for POC detection of TC, which demonstrated high sensitivity, selectivity, and reproducibility. In addition to homogeneous visual detection in a 96-well plate, a CuNCs@MOF-5-contained agarose gel array was easily fabricated to achieve direct detection of TC in milk without any pretreatment, thanks to the size-sieving effect of the gel. Moreover, a test paper array was also put forward for low-cost TC detection, which indicates the extensibility and practicability of this sensing strategy.

Effects of Roflumilast on Patients with Chronic Obstructive Pulmonary Disease Treated with Inhaled Corticosteroid/Long-Acting ß2 Agonist: A Meta-analysis.

Objective: Roflumilast is a novel therapeutic drug for chronic obstructive pulmonary disease (COPD). This study was designed to evaluate the efficacy and safety of roflumilast combining inhaled corticosteroid (ICS)/long-acting ß2 agonist (LABA) in treating COPD patients through the meta-analysis. Methods: Randomized controlled trials of roflumilast combining ICS/LABA in treating patients with severe and profound COPD were searched from PubMed, Cochrane Library, and Embase databases from their establishment to February 2022. The quality of included studies was assessed by Cochrane risk bias assessment tool. The main outcomes of these studies should include at least one of the following clinical outcome indicators: forced expiratory volume in one second (FEV1), exacerbation rate, and adverse events (AEs) such as diarrhea, nasopharyngitis, and headache. Results: Six articles were included in the study, including 9,715 patients. Meta-analysis revealed that compared with placebo, roflumilast gained superiority for severe COPD patients treated with ICS/LABA combinations in FEV1 before bronchodilator administration (MD = 46.62, 95% CI (30.69, 62.55), P < 0.00001), FEV1 after bronchodilator administration (MD = 45.62, 95% CI (34.95, 56.28), P < 0.00001), and COPD exacerbation rate (RR = 0.90, 95% CI (0.87, 0.94), P = 0.001). In terms of safety, the incidence of diarrhea, headache, nausea, weight loss, back pain, loss of appetite, and insomnia was notably higher in the roflumilast group than in the placebo group. Conclusion: Roflumilast is suggested to be significantly effective for severe COPD patients with ICS/LABA combination therapy, which reduces the exacerbation rate but also leads to PDE4 inhibitor-related adverse reactions.

Stable and sensitive sensor for alkaline phosphatase based on target-triggered wavelength tuning of fluorescent copper nanoclusters.

Generally, the volatility and vulnerability of intensity signal largely reduced the reproducibility and stability of fluorescent nanosensor. Herein, we proposed a novel and stable fluorescent sensor by employing the wavelength shift of copper nanoclusters (CuNCs) as signal readout. The thymine-templated CuNCs were prepared by facile and rapid one-pot reduction method. Interestingly and importantly, it was found that the fluorescence wavelength of CuNCs could be precisely tuned by manganese ion (Mn2+). Through systematic investigation, it was further proved that the wavelength readout of CuNCs is significantly more stable than intensity readout. Since alkaline phosphatase (ALP) can catalyze the hydrolysis of phosphorylated ascorbic acid into ascorbic acid (AA) which can trigger the decomposition of MnO2 nanosheets (NS) into Mn2+, a stable sensor for sensitive ALP detection was constructed based on precise wavelength tuning of fluorescent CuNCs. The sensor exhibited good linear response to ALP over the range from 0.025 to 10 U/L with a detection limit of 0.008 U/L. Additionally, this sensor was also extended to assay two typical ALP inhibitors (Na3VO4 and EDTA) with reasonable results. Last but not least, it was confirmed that the detection results of ALP in real serum samples with this sensor were highly consistent with the data from clinical test, which was mainly attributed to the improved stability and practicability of wavelength readout-based sensor.

Response to Pralsetinib Observed in Meningeal-Metastatic EGFR-Mutant NSCLC With Acquired RET Fusion: A Brief Report.

Introduction: RET is well known as an important driver gene in NSCLC. Moreover, RET is a rare acquired resistance mechanism to EGFR-mutant NSCLC. Only 36 NSCLC cases of coexistence of EGFR and RET were reported previously worldwide. So far, there have been no reports on the following: (1) whether combination of EGFR tyrosine kinase inhibitor (TKI) and RET TKI works for meningeal metastasis; (2) the concentrations of EGFR TKI and RET TKI in the cerebrospinal fluid (CSF) and plasma; and (3) whether RET fusions and EGFR mutation happened in the same clone or not. Methods: We reported a patient with an EGFR-mutant NSCLC with acquired RET fusions and meningeal metastasis treated with pralsetinib and osimertinib; the specimen was analyzed by next-generation sequencing (Illumina NovaSeq 6000 platform). Symptom improvement and magnetic resonance imaging scan were used for effect evaluation. Furthermore, we determined the concentrations of pralsetinib and osimertinib in CSF and plasma by means of liquid chromatography tandem mass spectrometry. We also detected RET fusion and EGFR L858R mutation by methods of fluorescence in situ hybridization and immunohistochemistry with continuous sections to analyze whether RET fusions coexist with EGFR mutation in the same clone or not. Results: The allele frequency of the RET fusion was detected to be 12.88%. This patient achieved a partial response, indicating pralsetinib combined with osimertinib may be clinically beneficial for meningeal metastasis in patients harboring acquired coexistent RET fusions. The concentrations of pralsetinib in the CSF and plasma were 704.76 nM and 91.31 µM, whereas those of osimertinib in the CSF and plasma were 23.70 nM and 2148.94 nM, respectively. RET fusion was found in the same clone of EGFR L858R mutation. Conclusions: Our finding of this case indicated that RET fusion and EGFR mutation occur in the same population of cell clones, rather than in different cell clones. Combined pralsetinib may be an effective way to overcome the resistance, even for meningeal metastasis, owing to high CSF distribution of pralsetinib.

Tumor necrosis factor-α-inducing protein of Helicobacter pylori promotes epithelial-mesenchymal transition and cancer stem-like cells properties via activation of Wnt/ß-catenin signaling pathway in gastric cancer cells.

Tumor necrosis factor-α-inducing protein (Tipα) is a newly identified toxin that promotes the inflammation and carcinogenesis caused by Helicobacter pylori. However, its mechanism of pathogenesis is still unclear. To investigate the carcinogenic mechanisms of Tipα, SGC7901 cells and SGC7901-derived cancer stem-like cells (CSCs) were stimulated by recombinant Tipα with or without Wnt/ß-catenin signaling inhibitor XAV939. qRT-PCR and Western blotting were employed to detect expression of epithelial-mesenchymal transition (EMT), CSCs markers and downstream target genes of this signaling pathway. The cell migration ability was measured by wound healing assay and transwell assay. Our results indicated that Tipα promoted CSC properties of SGC7901 spheroids, including increased expression of CSC specific surface markers CD44, Oct4 and Nanog and an increased capacity for self-renewal. Tipα activated Wnt/ß-catenin signaling in both SGC7901 cells or CSCs. Furthermore, Tipα induced the EMT and increased the expressions of downstream target genes of this signaling, including c-myc, cyclin D1 and CD44. However, XAV939 pretreatment inhibited Tipα-induced EMT and CSC properties in SGC7901 cells or CSCs. These results suggest that Tipα promotes EMT and CSC-like properties in gastric cancer cells through activation of Wnt/ß-catenin signaling pathway, thereby accelerating the progression of gastric cancer.