Folate-PEG-PROTAC Micelles for Enhancing Tumor-Specific Targeting Proteolysis In Vivo.

Proteolysis targeting chimeras (PROTACs) technology is rapidly developed as a novel and selective medicinal strategy for the degradation of cellular proteins in cancer therapy. However, the applications of PROTACs as heterobifunctional molecules are largely limited by high molecular weight, low bioavailability, poor permeability, insufficient targeting, and low efficacy in vivo. Herein, self-assembling micelles of FA-PEG-PROTAC are designed for cancer cell selective targeting and reductive-response proteolysis in tumor-bearing mice. FA-PEG-PROTAC is prepared by conjugating folic acid (FA)-PEG with EGFR-targeting PROTAC via a disulfide bond. The FA-PEG-PROTAC micelles, formed by self-assembling, are demonstrated to significantly improve tumor targeting efficacy and exhibit excellent anti-tumor efficacy in the mouse xenograft model compared to the traditional PROTACs. The strategy of applying self-assembled FA-PEG-PROTAC micelles in tumor therapy can not only improve targeted proteolysis efficiency but also broaden applications in the development of PROTAC-based drugs.

PHLDA1 is a P53 target gene involved in P53-mediated cell apoptosis.

Pleckstrin homeolike domain, family A, member 1 (PHLDA1) is a multifunctional protein that plays diverse roles in A variety of biological processes, including cell death, and hence its altered expression has been found in different types of cancer. Although studies have shown a regulatory relationship between p53 and PHLDA1, the molecular mechanism is still unclear. Especially, the role of PHLDA1 in the process of apoptosis is still controversial. In this study, we found that the expression of PHLDA1 in human cervical cancer cell lines was correlated with the up-expression of p53 after treatment with apoptosis-inducing factors. Subsequently, the binding site and the binding effect of p53 on the promoter region of PHLDA1 were verified by our bioinformatics data analysis and luciferase reporter assay. Indeed, we used CRISPR-Cas9 to knockout the p53 gene in HeLa cells and further confirmed that p53 can bind to the promoter region of PHLDA1 gene, and then directly regulate the expression of PHLDA1 by recruiting P300 and CBP to change the acetylation and methylation levels in the promoter region. Finally, a series of gain-of-function experiments further confirmed that p53 re-expression in HeLap53-/- cell can up-regulate the reduction of PHLDA1 caused by p53 knockout, and affect cell apoptosis and proliferation. Our study is the first to explore the regulatory mechanism of p53 on PHLDA1 by using the p53 gene knockout cell model, which further proves that PHLDA1 is a target-gene in p53-mediated apoptosis, and reveals the important role of PHLDA1 in cell fate determination.

HIF-1α regulates the cell viability in radioiodine-resistant papillary thyroid carcinoma cells induced by hypoxia through PKM2/NF-κB signaling pathway.

The curative treatment options for papillary thyroid cancer (PTC) encompass surgical intervention, radioactive iodine administration, and chemotherapy. However, the challenges of radioiodine (RAI) resistance, metastasis, and chemotherapy resistance remain inadequately addressed. The objective of this study was to investigate the protective role of hypoxia-inducible factor-1α (HIF-1α) in 131 I-resistant cells and a xenograft model under hypoxic conditions, as well as to explore potential mechanisms. The effects of HIF-1α on 131 I-resistant BCPAP and TPC-1 cells, as well as the xenograft model, were assessed in this study. Cell viability, migration, invasion, and apoptosis rates were measured using Cell Counting Kit-8, wound-healing, Transwell, and flow cytometry assays. Additionally, the expressions of Ki67, matrix metalloproteinase-9 (MMP-9), and pyruvate kinase M2 (PKM2) were examined using immunofluorescence or immunohistochemistry assays. Sodium iodide symporter and PKM2/NF-κBp65 relative protein levels were detected by western blot analysis. The findings of our study indicate that siHIF-1α effectively inhibits cell proliferation, cell migration, and invasion in 131 I-resistant cells under hypoxic conditions. Additionally, the treatment of siHIF-1α leads to alterations in the relative protein levels of Ki67, MMP-9, PKM2, and PKM2/NF-κBp65, both in vivo and in vitro. Notably, the effects of siHIF-1α are modified when DASA-58, an activator of PKM2, is administered. These results collectively demonstrate that siHIF-1α reduces cell viability in PTC cells and rat models, while also mediating the nuclear factor-κB (NF-κB)/PKM2 signaling pathway. Our findings provide a new rationale for further academic and clinical research on RAI-resistant PTC.

[Microbial production of S-adenosyl-l-methionine: a review].

S-adenosyl-l-methionine (SAM) is ubiquitous in living organisms and plays important roles in transmethylation, transsulfuration and transamination in organisms. Due to its important physiological functions, production of SAM has attracted increasing attentions. Currently, researches on SAM production mainly focus on microbial fermentation, which is more cost-effective than that of the chemical synthesis and the enzyme catalysis, thus easier to achieve commercial production. With the rapid growth in SAM demand, interests in improving SAM production by developing SAM hyper-producing microorganisms aroused. The main strategies for improving SAM productivity of microorganisms include conventional breeding and metabolic engineering. This review summarizes the recent research progress in improving microbial SAM productivity to facilitate further improving SAM productivity. The bottlenecks in SAM biosynthesis and the solutions were also addressed.

Biomedical named entity recognition based on fusion multi-features embedding.

BACKGROUND: With the exponential increase in the volume of biomedical literature, text mining tasks are becoming increasingly important in the medical domain. Named entities are the primary identification tasks in text mining, prerequisites and critical parts for building medical domain knowledge graphs, medical question and answer systems, medical text classification. OBJECTIVE: The study goal is to recognize biomedical entities effectively by fusing multi-feature embedding. Multiple features provide more comprehensive information so that better predictions can be obtained. METHODS: Firstly, three different kinds of features are generated, including deep contextual word-level features, local char-level features, and part-of-speech features at the word representation layer. The word representation vectors are inputs into BiLSTM as features to obtain the dependency information. Finally, the CRF algorithm is used to learn the features of the state sequences to obtain the global optimal tagging sequences. RESULTS: The experimental results showed that the model outperformed other state-of-the-art methods for all-around performance in six datasets among eight of four biomedical entity types. CONCLUSION: The proposed method has a positive effect on the prediction results. It comprehensively considers the relevant factors of named entity recognition because the semantic information is enhanced by fusing multi-features embedding.

Improvement of S-adenosyl-L-methionine production in Saccharomyces cerevisiae by atmospheric and room temperature plasma-ultraviolet compound mutagenesis and droplet microfluidic adaptive evolution.

To improve S-Adenosyl-L-methionine (a compound with important physiological functions, SAM) production, atmospheric and room temperature plasma and ultraviolet-LiCl mutagenesis were carried out with Saccharomyces cerevisiae strain ZY 1-5. The mutants were screened with ethionine, L-methionine, nystatin and cordycepin as screening agents. Adaptive evolution of a positive mutant UV6-69 was further performed by droplet microfluidics cultivation with ethionine as screening pressure. After adaptation, mutant T11-1 was obtained. Its SAM titer in shake flask fermentation reached 1.31 g/L, which was 191% higher than that of strain ZY 1-5. Under optimal conditions, the SAM titer and biomass of mutant T11-1 in 5 L bioreactor reached 10.72 g/L and 105.9 g dcw/L (142.86% and 34.22% higher than those of strain ZY 1-5), respectively. Comparative transcriptome analysis between strain ZY 1-5 and mutant T11-1 revealed the enhancements in TCA cycle and gluconeogenesis/glycolysis pathways as well as the inhibitions in serine and ergosterol synthesis of mutant T11-1. The elevated SAM synthesis of mutant T11-1 may attribute to the above changes. Taken together, this study is helpful for industrial production of SAM.

Emodin inhibits the proliferation of papillary thyroid carcinoma by activating AMPK.

Emodin has been demonstrated to serve antitumor roles in a variety of tumor types, but the effect of emodin on papillary thyroid carcinoma and its molecular mechanisms remain unclear. In the current study, the role of emodin on papillary thyroid carcinoma was analyzed in vitro and in vivo. TPC-1 cells were treated with emodin (0, 10, 25 or 50 µM), and cell viability and apoptosis were detected using Cell Counting Kit-8 and flow cytometry, respectively. The expression levels of AMPK-associated proteins were examined using western blot analysis. To study the effect of emodin on the AMPK pathway, AMPK activator, AICAR and an AMPK inhibitor, Dorsomorphin, were used in TPC-1 cells. In vivo, mice were used to confirm the mechanism of emodin on papillary thyroid carcinoma. The results of the current study indicated that emodin treatment induced cell apoptosis and cell cycle arrest in TPC-1 cells. Furthermore, the inhibitory effect increased in a dose dependent manner. Following emodin treatment, the cell viability of TPC-1 cells was significantly decreased, and apoptosis rate increased (P<0.05). Furthermore, the expression levels of AMPK were increased in the emodin group compared with the control group (P<0.05). Similar effects were observed following AMPK activator treatment in TPC-1 cells. Following AMPK activator treatment, cell proliferation and the cell cycle were inhibited. Also, the AMPK inhibitor was demonstrated to mediate the therapeutic effect of emodin. In addition, the results of the present study demonstrated that emodin inhibited the MEK/ERK pathway. Additionally, the in vivo results of the current study were consistent with those in vitro. In conclusion, the current study demonstrated that the administration of Emodin inhibited the proliferation of papillary thyroid cancer cells via activating AMPK pathway activity.

U.S. Phase I First-in-human Study of Taletrectinib (DS-6051b/AB-106), a ROS1/TRK Inhibitor, in Patients with Advanced Solid Tumors.

PURPOSE: Taletrectinib (DS-6051b/AB-106) is an oral, tyrosine kinase inhibitor of ROS1 and NTRK with potent preclinical activity against ROS1 G2032R solvent-front mutation among others. We report the first-in-human U.S. phase I results of taletrectinib. PATIENTS AND METHODS: Patients ≥18 years old with neuroendocrine tumors, with tumor-induced pain, or tumors harboring ROS1/NTRK rearrangements were eligible. Accelerated titration followed by modified continuous reassessment method and escalation with overdose control was used (50-1,200 mg once daily or 400 mg twice daily). Primary objectives were safety/tolerability, and MTD determination. Secondary objectives were food-effect pharmacokinetics and antitumor activity. RESULTS: A total of 46 patients were enrolled. Steady-state peak concentration (C max) and exposure (AUC0-8) increased dose dependently from 50-mg to 800-mg once-daily doses. The ratio of the geometric mean of AUC0-24 between low-fat-diet-fed/fasted state was 123% (90% confidence interval, 104%-149%). Dose-limiting toxicities (grade 3 transaminases increase) occurred in two patients (1,200-mg once-daily dose). MTD was 800 mg once daily. Most common treatment-related adverse events were nausea (47.8%), diarrhea (43.5%), and vomiting (32.6%). Pain score reductions were observed in the 800-mg once-daily dose cohort. Confirmed objective response rate was 33.3% among the six patients with RECIST-evaluable crizotinib-refractory ROS1+ NSCLC. One patient with TPM3-NTRK1 differentiated thyroid cancer achieving a confirmed partial response of 27 months at data cutoff. We identified a cabozantinib-sensitive ROS1 L2086F as an acquired taletrectinib-resistance mutation. CONCLUSIONS: Taletrectinib has manageable toxicities at the MTD of 800 mg daily. Preliminary efficacy was observed in patients with crizotinib-refractory ROS1+ NSCLC.

Mechanism of DNA translocation underlying chromatin remodelling by Snf2.

Chromatin remodellers include diverse enzymes with distinct biological functions, but nucleosome-sliding activity appears to be a common theme1,2. Among the remodelling enzymes, Snf2 serves as the prototype to study the action of this protein family. Snf2 and related enzymes share two conserved RecA-like lobes3, which by themselves are able to couple ATP hydrolysis to chromatin remodelling. The mechanism by which these enzymes couple ATP hydrolysis to translocate the nucleosome along the DNA remains unclear2,4-8. Here we report the structures of Saccharomyces cerevisiae Snf2 bound to the nucleosome in the presence of ADP and ADP-BeFx. Snf2 in the ADP-bound state adopts an open conformation similar to that in the apo state, and induces a one-base-pair DNA bulge at superhelix location 2 (SHL2), with the tracking strand showing greater distortion than the guide strand. The DNA distortion propagates to the proximal end, leading to staggered translocation of the two strands. The binding of ADP-BeFx triggers a closed conformation of the enzyme, resetting the nucleosome to a relaxed state. Snf2 shows altered interactions with the DNA in different nucleotide states, providing the structural basis for DNA translocation. Together, our findings suggest a fundamental mechanism for the DNA translocation that underlies chromatin remodelling.

Mechanism of chromatin remodelling revealed by the Snf2-nucleosome structure.

Chromatin remodellers are helicase-like, ATP-dependent enzymes that alter chromatin structure and nucleosome positions to allow regulatory proteins access to DNA. Here we report the cryo-electron microscopy structure of chromatin remodeller Switch/sucrose non-fermentable (SWI2/SNF2) from Saccharomyces cerevisiae bound to the nucleosome. The structure shows that the two core domains of Snf2 are realigned upon nucleosome binding, suggesting activation of the enzyme. The core domains contact each other through two induced Brace helices, which are crucial for coupling ATP hydrolysis to chromatin remodelling. Snf2 binds to the phosphate backbones of one DNA gyre of the nucleosome mainly through its helicase motifs within the major domain cleft, suggesting a conserved mechanism of substrate engagement across different remodellers. Snf2 contacts the second DNA gyre via a positively charged surface, providing a mechanism to anchor the remodeller at a fixed position of the nucleosome. Snf2 locally deforms nucleosomal DNA at the site of binding, priming the substrate for the remodelling reaction. Together, these findings provide mechanistic insights into chromatin remodelling.

A New Direction of Cancer Classification: Positive Effect of Low-Ranking MicroRNAs.

OBJECTIVES: Many studies based on microRNA (miRNA) expression profiles showed a new aspect of cancer classification. Because one characteristic of miRNA expression data is the high dimensionality, feature selection methods have been used to facilitate dimensionality reduction. The feature selection methods have one shortcoming thus far: they just consider the problem of where feature to class is 1:1 or n:1. However, because one miRNA may influence more than one type of cancer, human miRNA is considered to be ranked low in traditional feature selection methods and are removed most of the time. In view of the limitation of the miRNA number, low-ranking miRNAs are also important to cancer classification. METHODS: We considered both high- and low-ranking features to cover all problems (1:1, n:1, 1:n, and m:n) in cancer classification. First, we used the correlation-based feature selection method to select the high-ranking miRNAs, and chose the support vector machine, Bayes network, decision tree, k-nearest-neighbor, and logistic classifier to construct cancer classification. Then, we chose Chi-square test, information gain, gain ratio, and Pearson's correlation feature selection methods to build the m:n feature subset, and used the selected miRNAs to determine cancer classification. RESULTS: The low-ranking miRNA expression profiles achieved higher classification accuracy compared with just using high-ranking miRNAs in traditional feature selection methods. CONCLUSION: Our results demonstrate that the m:n feature subset made a positive impression of low-ranking miRNAs in cancer classification.

Acetylsalicylic acid, but not clopidogrel, inhibits therapeutically induced cerebral arteriogenesis in the hypoperfused rat brain.

This study investigated the effects of acetylsalicylic acid (ASA) and clopidogrel, standardly used in the secondary prevention of vascular occlusions, on cerebral arteriogenesis in vivo and in vitro. Cerebral hypoperfusion was induced by three-vessel occlusion (3-VO) in rats, which subsequently received vehicle, ASA (6.34 mg/kg), or clopidogrel (10 mg/kg). Granulocyte colony-stimulating factor (G-CSF), which enhanced monocyte migration in an additional cell culture model, augmented cerebrovascular arteriogenesis in subgroups (40 µg/kg). Cerebrovascular reactivity and vessel diameters were assessed at 7 and 21 days. Cerebrovascular reserve capacity was completely abolished after 3-VO and remained severely compromised after 7 (-14±14%) and 21 (-5±11%) days in the ASA groups in comparison with controls (4±5% and 10±10%) and clopidogrel (4±13% and 10±8%). It was still significantly decreased when ASA was combined with G-CSF (1±4%) compared with G-CSF alone (20±8%). Posterior cerebral artery diameters confirmed these data. Monocyte migration into the vessel wall, improved by G-CSF, was significantly reduced by ASA. Acetylsalicylic acid, but not clopidogrel, inhibits therapeutically augmented cerebral arteriogenesis.

Predictive value of serum uric acid on cardiovascular disease and all-cause mortality in urban Chinese patients.

BACKGROUND: The association between increased serum uric acid (SUA) levels and cardiovascular risk has been debated for decades. Several large studies have provided conflicting results regarding the clinical significance of elevated SUA levels in cardiovascular disease (CVD) or cerebrovascular disease. The aim of this study was to investigate the relationship between SUA and CVD and all-cause mortality and their potential diagnostic value. METHODS: A total of 3570 in-patients ranging in age from 56 to 95 years (mean (67.36 +/- 11.36) years) were selected from 20 hospitals in Beijing and Shanghai. A carefully designed questionnaire was used to gather baseline data of each patient. All patients were divided into two main groups according to their SUA levels: high SUA and normal SUA groups. Serum indices and other important parameters were measured. RESULTS: Compared with normal SUA group, high SUA group had significant difference in systolic blood pressure (SBP), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), body mass index (BMI), and age (P < 0.05 or P < 0.01). High SUA prevailed in female and patients with history of essential hypertension, while history of smoking and diabetes showed no significant difference between two groups. All-cause and CVD mortality occurred more frequently in high SUA group than in normal SUA group. In the accumulative survival analysis, high SUA group had lower survival rate than normal SUA group both in CVD and all-cause mortality. COX regression analysis indicated that the history of smoking, age and high SUA were independent risk factors for the development of CVD. CONCLUSIONS: These preliminary observations suggest that patients with high SUA levels would face higher risk of mortality. SUA measurement may be applied as a routine predictor for clinical assessment.

[Multi-factor model of quality of life in patients with acute coronary syndrome].

OBJECTIVE: To detect the risk factors of quality of life (QOL) in patients with acute coronary syndrome (ACS), so as to help doctors to recognize the risk population with impaired QOL. METHODS: 403 hospitalized ACS patients, 252 males and 151 females, aged 67 12, 168 with ST-segment elevation myocardial infarction (STEMI), 4 with non-ST-segment elevation myocardial infarction (NSTEMI), and 74 with unstable angina pectoris (UAP), were surveyed with short-form-36 (SF-36) scale (Chinese version), including physical component summary (PCS) and mental component summary (MCS) so as to analyze the QOL, hospital anxiety depression scales (HADS) so as to detect the anxiety status. Multiple linear regression analysis was conducted to identify the variables associated with QOL. RESULTS: Of the 403 patients 84 (20.8%) suffered from anxiety, 43 (10.7%) suffered from depression, and 144 (35.7%) suffered from depression combined with anxiety symptoms . Age (r = -0.237, P < 0.001), being female (r = -0.183, P < 0.001), depression (r = -0.180; P < 0.001), and anxiety (r = -0.211, P <0. 001) were independent risk factors of physical QOL. Age (r = -0.117, P = 0.01), depression (r =-0.169, P = 0.004), and anxiety (r = -0.215, P < 0.001) were independently negatively correlated with mental QOL. Smoking was unexpectedly a protective factor for MCS (r = 0.157, P = 0.001). CONCLUSION: Depression and anxiety are common in patients diagnosed as with ACS, and appear to be related to significant worsening of QOL. The patients being female, with elder age, and suffering from depression and/or anxiety may be with impaired QOL, and need more care and effective intervention.

[The relationship between ankle brachial index and all-cause and cardiovascular disease mortality in Chinese metabolic syndrome male cohort].

OBJECTIVE: Ankle brachial index (ABI) is thought to be an efficient means of objectively assessing the potency of lower extremity arterial system. This study is aimed to evaluate the relationship between ABI and cardiovascular disease CVD mortality in Chinese male patients with metabolic syndrome (MS). METHODS: 1224 Chinese male patients with MS were selected from Beijing and Shanghai and the baseline examinations were carried out. All the participants were divided into 2 main groups: ABI < or = 0.9 (n = 268) and ABI 0.9 - 1.4 (n = 956). and they were followed up for (13.2 +/- 2.7) months. RESULTS: As to baseline characteristics, age, systolic blood pressure (SBP), hypertensive disease and diabetes mellitus morbidity and smoking history had significant difference between the 2 groups (P < 0.05 or P < 0.01). All-cause mortality and CVD mortality decreased gradually while the ABI increased from 0.4 to 1.4. With Cox regression analysis, relative ratio (RR) value of all-cause mortality and CVD mortality also showed the decreasing trend with the rising of ABI. CONCLUSION: In Chinese male patients with MS, ABI is one of the most important parameters in indicating possible prognosis and foreseeing all-cause and CVD mortality. Male subjects with relatively old age, higher systolic blood pressure, hypertensive disease and diabetes mellitus morbidity, smoking history may be associated with lower ABI (< or = 0.9) and relatively higher all-cause and CVD mortality. Our results suggest the urgent need for frequent measurement of the ABI in clinical practice before diagnosing peripheral artery disease and making therapeutic decision, especially in some high-risk population such as male patients with MS.

[The relation between post-acute coronary syndrome anxiety and serum levels of inflammatory factors].

OBJECTIVE: To explore the role of inflammatory factors (interleukin-6, tumor necrosis factor alpha, high sensitive C reactive protein) in the pathogenesis of anxiety after acute coronary syndrome (ACS) by investigating the serum levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha) and high sensitive C reactive protein (hsCRP). METHODS: Serum IL-6, TNFalpha and hsCRP levels were measured in 105 ACS patients within 7 days after onset of the event. Symptoms of anxiety were evaluated by self-reporting standardized questionnaire, using a validated Chinese version of Hospital Anxiety and Depression Scale (HADS-A)-Anxiety Subscale (7 items) within 72 hours of the event. Demographic and clinical data including cardiac risk factors were recorded. RESULTS: The median of TNFalpha was lower in the anxious patients with ACS than that of non-anxious ones (44.55 vs 61.70, P = 0.004). Neither the levels of hsCRP nor the levels of IL-6 were found to be different between the groups with anxiety and without. CONCLUSION: Anxiety after ACS does not increase the inflammatory reaction in the ACS patients.