Biologically active isoquinoline alkaloids covering 2019-2022.

Isoquinoline alkaloids are an important class of natural products that are abundant in the plant kingdom and exhibit a wide range of structural diversity and biological activities. With the deepening of research in recent years, more and more isoquinoline alkaloids have been isolated and identified and proved to contain a variety of biological activities and pharmacological effects. In this review, we introduce the research progress of isoquinoline alkaloids from 2019 to 2022, mainly in the part of biological activities, including antitumor, antimicrobial, antidiabetic, antiviral, anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, analgesic, and other activities. This study provides a clear direction for the rational development and utilization of isoquinoline alkaloids, suggesting that these alkaloids have great potential in the field of drug research.

Enlarged Perivascular Space in the Basal Ganglia is Associated with Cerebral Venous Reflux in Patients with Recent Small Subcortical Infarction.

BACKGROUND: Research has linked enlarged perivascular spaces (EPVS) to cerebral venous reflux (CVR) in patients with hypertensive intracerebral hemorrhage, but it is unclear whether this association exists in recent small subcortical infarct (RSSI) patients. OBJECTIVE: This study aimed to investigate the correlation between EPVS and CVR in patients with RSSI. METHOD: This study included 297 patients, selected from patients with RSSI in the lenticulostriate artery admitted to the Department of Neurology of the First Affiliated Hospital of Zhengzhou University. CVR was assessed by time-of-flight magnetic resonance angiography (TOF-MRA). The relationship between EPVS and CVR was studied using multiple logistic regression analysis. RESULTS: This study included patients with an average age of 59.84±12.27 years, including 201 males (67.7%). CVR was observed in 40 (13.5%) patients. Compared to the group without CVR, the proportions of male patients and patients with a history of smoking and drinking were higher in the CVR group. The proportions of high-grade EPVS in the centrum semiovale region [23 cases (57.5%) vs. 108 cases (42.0%), p =0.067] and the basal ganglia region [30 cases (75.0%) vs. 133 cases (51.8%), p =0.006] were higher in the CVR group. After multiple logistic regression analysis, high-grade EPVS in the basal ganglia region was still associated with CVR (OR, 2.68; 95% CI, 1.22-5.87; p =0.014). CONCLUSION: In the population with RSSI, EPVS in basal ganglia is significantly associated with CVR, suggesting a close relationship between venous dysfunction and the formation of EPVS.

Design and test of rack-integrated cavity combiner for China initiative accelerator driven system project.

The next-generation 650 MHz solid state power amplifier designed by the Institute of Modern Physics will utilize 24 modules with an output power of 60 kW. The outputs of each of the 12 modules will be combined using a 12-in-1 rectangular cavity combiner integrated into the rack. This cavity combiner, requiring only a single stage to combine power, is characterized by a minimal power loss and a high combining efficiency. The input couplers of the combiner are adjustable to change the number of combination channels. In the event of one amplifier module failure, the corresponding port can be adjusted to decouple, transforming the combiner to an (N-1)-channel combiner with a combining efficiency decay of 0.2%. The prototype of the combiner has been fabricated and tested with a small signal. The combining efficiency is 98.5%. In this paper, we will validate the feasibility of the combiner from the design, simulation, and experiment.

Application and teaching of computer molecular simulation embedded technology and artificial intelligence in drug research and development.

With the continuous development of the pharmaceutical industry, people have always paid attention to the safety and effectiveness of drugs, including innovative drugs and generic drugs. For pharmaceutical companies as manufacturers, drug development is a very lengthy process that requires high costs, millions of man-hours, thousands of trials, and the mobilization of hundreds of researchers. Therefore, efforts need to be made to develop drugs with high safety and effectiveness. Drug research and development plays an important role today. Based on this, this article applied computer molecular simulation embedded technology and artificial intelligence technology to drug research and development. First, the problems faced in the research and development of anti-inflammatory disease-dependent tumor drugs were introduced, and then the applications of computer molecular simulation embedded technology and artificial intelligence technology in drug research and development were analyzed. Subsequently, the application of artificial intelligence in drug research and development teaching was analyzed, and a teaching system based on computer molecular simulation embedded technology and artificial intelligence was designed. Finally, the application effects of computer molecular simulation embedded technology and artificial intelligence technology were analyzed, and a feasible conclusion was drawn. The use of computer molecular simulation embedded technology and artificial intelligence technology can greatly improve the efficiency of drug research and development, and the research and development safety of imatinib mesylate has been improved by 7%. On the other hand, it can improve students' learning interest and stimulate their learning interest, and students' drug research and development capabilities have been improved. Drug research and development for inflammatory-dependent tumors has good application prospects.

Efficacy of pterostilbene suppression on Aspergillus flavus growth, aflatoxin B1 biosynthesis and potential mechanisms.

Aspergillus flavus, a widespread saprotrophic filamentous fungus, could colonize agricultural crops with aflatoxin contamination, which endangers food security and the agricultural economy. A safe, effective and environmentally friendly fungicide is urgently needed. Pterostilbene, a natural phytoalexin originated from Pterocarpus indicus Willd., Vaccinium spp. and Vitis vinifera L., has been reported to possess excellent antimicrobial activity. More importantly, it is quite safe and healthy. In our screening tests of plant polyphenols for the inhibition of A. flavus, we found that pterostilbene evidently inhibited mycelial growth of Aspergillus flavus (EC50 = 15.94 µg/mL) and the inhibitory effect was better than that of natamycin (EC50 = 22.01 µg/mL), which is a natural product widely used in food preservation. Therefore, we provided insights into the efficacy of pterostilbene suppression on A. flavus growth, aflatoxin B1 biosynthesis and its potential mechanisms against A. flavus in the present study. Here, pterostilbene at concentrations of 250 and 500 µg/mL could effectively inhibit the infection of A. flavus on peanuts. And the biosynthesis of the secondary metabolite aflatoxin B1 was also inhibited. The antifungal effects of pterostilbene are exerted by inducing a large amount of intracellular reactive oxygen species production to bring the cells into a state of oxidative stress, damaging cellular biomolecules such as DNA, proteins and lipids and destroying the integrity of the cell membrane. Taken together, our study strongly supported the fact that pterostilbene could be considered a safe and effective antifungal agent against A. flavus infection.

Antimicrobial activity of natural and semi-synthetic carbazole alkaloids.

Since the first natural carbazole alkaloid, murrayanine, was isolated from Mwraya Spreng, carbazole alkaloid derivatives have been widely concerned for their anti-tumor, anti-viral and anti-bacterial activities. In recent decades, a growing body of data suggest that carbazole alkaloids and their derivatives have different biological activities. This is the first comprehensive description of the antifungal and antibacterial activities of carbazole alkaloids in the past decade (2012-2022), including natural and partially synthesized carbazole alkaloids in the past decade. Finally, the challenges and problems faced by this kind of alkaloids are summarized. This paper will be helpful for further exploration of this kind of alkaloids.

Analysis of the risk factors for secondary hemorrhage after abdominal surgery.

Introduction: This study aimed to conduct a clinical review and analysis to recommend options for the prevention and treatment of postoperative hemorrhage. Patients and Methods: A total of 138 patients who experienced postoperative hemorrhage after abdominal surgery in the period between January 2015 and December 2020 at the Sir Run Run Shaw Hospital, affiliated to Zhejiang University School of Medicine, participated in this study. They were divided into a group with primary bleeding only and a secondary bleeding group. Univariate and multivariate statistical analyses were performed, followed by plotting of cumulative hazard and survival curves for the two groups. Results: The main factors of interest found to be associated with secondary hemorrhage were duration of the operation, the time of the first bleeding incident, intervention time, performance of combined organ resection, use of surgical intervention, occurrence of abdominal infection, admission to the intensive care unit (ICU), postoperative length of stay, and total hospitalization expenses. Among these, a long operative duration (>5 h) and an extended intervention time (>5 h) were identified as independent predictors of risk of secondary hemorrhage. Conclusions: Secondary hemorrhage after abdominal surgery is mainly associated with subjective human factors, and it is an important cause of poor prognosis and even death. Proper reductions in operation time and implementation of a quick response to bleeding are the key factors in tackling bleeding. Further reduction in the rates of postoperative hemorrhage and mortality will require a concerted effort by surgeons in terms of both intraoperative surgical techniques and postoperative management.

Case report: A case study on the treatment using icaritin soft capsules in combination with lenvatinib achieving impressive PR and stage reduction in unresectable locally progressive pancreatic cancer and a literature review.

Background: Pancreatic cancer is one of the most deadly malignancies in the world. It is characterized by rapid progression and a very poor prognosis. The five-year survival rate of pancreatic cancer in China is only 7.2%, which is the lowest among all cancers and the use of combined paclitaxel albumin, capecitabine, and digital has been the clinical standard treatment for advanced pancreatic cancer since 1997. Also, the application of multidrug combinations is often limited by the toxicity of chemotherapy. Therefore, there is an urgent need for a more appropriate and less toxic treatment modality for pancreatic cancer. Case presentation: The patient was a 79-year-old woman, admitted to the hospital with a diagnosis of unresectable locally advanced pancreatic cancer (T3N0M0, stage IIA), with its imaging showing overgrowth of SMV involvement and unresectable reconstruction of the posterior vein after evaluation. As the patient refused chemotherapy, lenvatinib (8 mg/time, qd) and icaritin soft capsules (three tablets/time, bid) were recommended according to our past experience and a few clinical research cases. The tumor lesion was greatly reduced by 57.5% after the treatment, and the extent of vascular involvement also decreased. The aforementioned medication resulted in a significant downstaging of the patient's tumor. Conclusion: Better results were achieved in the treatment with icaritin soft capsules and lenvatinib in this case. Because of its less toxic effect on the liver and kidney and bone marrow suppression, it was suitable to combine icaritin soft capsules with targeted drugs for treating intermediate and advanced malignancies, which brings hope to patients who cannot or refuse to take chemotherapy.

Adjuvant alternative cytokine-induced killer cell combined with natural killer cell immunotherapy improves the prognosis of post-mastectomy breast cancer.

Breast cancer is one of the most common cancers in women. Triple-negative breast cancer (TNBC) has a significantly worse prognosis due to the lack of endocrine receptors including estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). In this study, we investigated adjuvant cellular immunotherapy (CIT) in patients with post-mastectomy breast cancer. We enrolled 214 post-mastectomy breast cancer patients, including 107 patients in the control group (who received chemotherapy/radiotherapy/endocrine therapy) and the other 107 patients in the CIT group (who received chemotherapy/radiotherapy/endocrine therapy and subsequent immune cell infusion). Of these 214 patients, 54 had TNBC, including 26 patients in the control group and 28 patients in the CIT group. Survival analysis showed that the overall survival rate of patients treated with cellular immunotherapy was higher than that of patients who were not treated with CIT. Compared to those who received cytokine-induced killer (CIK) cells alone, the patients who received CIK combined with natural killer (NK) cell immunotherapy showed the best overall survival rate. In subgroup analyses, adjuvant CIT significantly improved the overall survival of patients in the TNBC subgroup and the patients who were aged over 50 years. Our study indicates that adjuvant CIK cell combined with NK cell treatment is an effective therapeutic strategy to prolong the survival of post-mastectomy patients, particularly for TNBC patients and those who are aged over 50 years.

Nomogram for predicting prognosis of patients with metastatic melanoma after immunotherapy: A Chinese population-based analysis.

Background: Previous studies indicated the evidence that baseline levels of thyroid antibodies, thyroid status, and serum lactate dehydrogenase (LDH) and M stage may influence the prognosis of patients with advanced or metastatic melanoma treated with immune checkpoint inhibitors that targets programmed cell death-1 (PD-1) or programmed death ligand 1, which reported that dramatic improvements in survival rates were observed; however, the presence of controversy has prevented consensus from being reached. Study objectives were to develop a nomogram to identify several prognostic factors in Chinese patients with metastatic melanoma receiving immunotherapy. Methods: This retrospective study included 231 patients from Sun Yat-sen University Cancer Center, and patients were split into internal cohort (n = 165) and external validation cohort (n = 66). We developed a nomogram for the prediction of response and prognosis on the basis of the levels of serum thyroid peroxidase antibody (A-TPO), free T3 (FT3), and LDH and M stage that were measured at the baseline of anti-PD-1 infusion. In addition, the follow-up lasted at least until 5 years after the treatment or mortality. RECIST v1.1 was used to classify treatment responses. Results: Chi-square test showed that PD-1 antibody was more effective in patients with melanoma with high level baseline FT4 or earlier M stage. A multivariate Cox analysis showed that baseline FT3 (P = 0.009), baseline A-TPO (P = 0.016), and LDH (P = 0.013) levels and M stage (P < 0.001) independently predicted overall survival (OS) in patients with melanoma. The above factors are integrated, and a prediction model is established, i.e., nomogram. Survival probability area-under-the-curve values of 1, 2, and 3 years in the training, internal validation, and external validation cohorts showed the prognostic accuracy and clinical applicability of nomogram (training: 0.714, 0.757, and 0.764; internal validation: 0.7171963, 0.756549, and 0.7651486; external validation: 0.748, 0.710, and 0.856). In addition, the OS of low-risk (total score ≤ 142.65) versus high-risk (total score > 142.65) patients varied significantly in both training group (P < 0.0001) and external validation cohort (P = 0.0012). Conclusions: According to this study, baseline biomarkers are associated with response to immunotherapy and prognosis among patients with metastatic melanoma. Treatment regimens can be tailor-made on the basis of these biomarkers.

The Antifungal Mechanism of Isoxanthohumol from Humulus lupulus Linn.

Humulus lupulus Linn. is a traditional medicinal and edible plant with several biological properties. The aims of this work were: (1) to evaluate the in vitro antifungal activity of H. lupulus ethanolic extract; (2) to study the in vitro and in vivo antifungal activity of isoxanthohumol, an isoprene flavonoid from H. lupulus, against Botrytis cinerea; and (3) to explore the antifungal mechanism of isoxanthohumol on B. cinerea. The present data revealed that the ethanolic extract of H. lupulus exhibited moderate antifungal activity against the five tested phytopathogenic fungi in vitro, and isoxanthohumol showed highly significant antifungal activity against B. cinerea, with an EC50 value of 4.32 µg/mL. Meanwhile, it exhibited moderate to excellent protective and curative efficacies in vivo. The results of morphologic observation, RNA-seq, and physiological indicators revealed that the antifungal mechanism of isoxanthohumol is mainly related to metabolism; it affected the carbohydrate metabolic process, destroyed the tricarboxylic acid (TCA) cycle, and hindered the generation of ATP by inhibiting respiration. Further studies indicated that isoxanthohumol caused membrane lipid peroxidation, thus accelerating the death of B. cinerea. This study demonstrates that isoxanthohumol can be used as a potential botanical fungicide for the management of phytopathogenic fungi.

Transcranial Sonography of the Substantia Nigra for the Differential Diagnosis of Parkinson's Disease and Other Movement Disorders: A Meta-Analysis.

This meta-analysis aimed to evaluate the accuracy of hyperechogenicity of the substantia nigra (SN) for the differential diagnosis of Parkinson's disease (PD) and other movement disorders. We systematically searched the PubMed, EMBASE, Cochrane Library, and China National Knowledge Infrastructure databases for relevant studies published between January 2015 and May 2020. Eligible articles comparing the echogenicity of the SN between patients with PD and those with other movement disorders were screened, and two independent reviewers extracted data according to the inclusion and exclusion criteria. Statistical analyses were conducted using STATA (version 15.0) (Stata Corporation, College Station, TX, USA), Review Manager 5.3 (Cochrane Collaboration), and Meta-DiSc1.4 to assess the pooled diagnostic value of transcranial sonography (TCS) for PD. Nine studies with a total of 1046 participants, including 669 patients with PD, were included in the final meta-analysis. Our meta-analysis demonstrated that hyperechogenicity of the SN had a pooled sensitivity and specificity of 0.85 (0.82, 0.87) and 0.71 (0.66, 0.75), respectively, for distinguishing idiopathic Parkinson's disease from other movement disorders. Furthermore, the area under the curve of the summary receiver operating characteristic was 0.94. Transcranial sonography of the SN is a valuable tool for the differential diagnosis of PD and other movement disorders.

Phenolic compounds from cultivated Glycyrrhiza uralensis and their PD-1/PD-L1 inhibitory activities.

One new compound (1) and fifteen known phenolic compounds (2-16) were isolated and identified from the roots and rhizomes of Glycyrrhiza uralensis, including ten flavonoids, four coumarins, and two benzofurans compounds. Their structures were identified by NMR and MS analysis. Most of these compounds showed weak PD-1/PD-L1 inhibitory activities with the inhibition ratios from 30 to 65% at 100 uM. To our knowledge, it is the first time that their PD-1/PD-L1 inhibition activities were reported.

[ClinicaAnalysis of osteosclerotic protein expression and bacterial distribution in periodontitis patients at different stages].

PURPOSE: To investigate the osteosclerin level and bacterial distribution in periodontitis patients at different stages, and to analyze the correlation between osteosclerin and the parameters of conventional periodontal examination. METHODS: Patients with periodontitis admitted to Guangzhou Huadu Maternal and Child Health Hospital from March 2017 to June 2019 were selected and divided into stage Ⅱ group (n=27), stage Ⅲ group (n=42) and stage Ⅳ group (n=22) according to the severity of periodontitis; meanwhile, 30 healthy individuals underwent physical examination in our hospital during the same period were selected as control group. Gingival crevicular fluid and plaque at buccal and lingual sites were collected for bacterial culture. The expression of osteosclerotin in gingival crevicular fluid was detected by enzyme-linked immunosorbent assay. The data were processed by SPSS 23.0 software package. Spearman correlation analysis was used to analyze the correlation between BI grade and osteosclerin, and correlation between PD, CAL and osteosclerin was determined by Pearson analysis. RESULTS: The mean PD and mean CAL of patients in stage Ⅱ group before and after treatment were significantly smaller than those in stage Ⅲ and Ⅳ group (P<0.05). The mean CAL of stage Ⅳ group before treatment was significantly greater than that of stage Ⅲ group (P<0.05). After treatment, the mean PD and mean CAL of three groups were all significantly smaller than those before treatment (P<0.05). The mean PD in stage Ⅲ group was significantly lower than that in stage Ⅳ group after treatment (P<0.05). Before treatment, the proportion of BI grade 2 in stage Ⅱ group was significantly higher than that in stage Ⅲ and Ⅳ group (85.19%, 19.05%, 18.18%, P<0.05). Before treatment, the proportion of BI grade 3 in stage Ⅲ group was significantly higher than that in stage Ⅱ group (64.29%, 14.81%, P<0.05). Before the treatment, the expression of osteosclerosis protein in stage Ⅱ group was significantly lower than that in stage Ⅲ and Ⅳ group (P<0.05). The levels of osteosclerin expression of three groups after treatment were all significantly lower than those before treatment (P<0.05). The expression of osteosclerosis protein in stage Ⅱ group was significantly lower than that in stage Ⅲ and Ⅳ group after treatment (P<0.05). PD, CAL and BI of patients with different stages of periodontitis were positively correlated with osclerosin in gingival crevicular fluid before and after treatment (P<0.05). The number of bacteria detected in stage Ⅳ group was significantly higher than that in stage Ⅲ group and stage Ⅱ group. The main bacteria in each group were anaerobic bacteria. The dominant bacteria were Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetes, Fusobacterium nucleatum, and Prevotella melaninogenicus. CONCLUSIONS: The expression level of osteosclerosin is closely related to PD, CAL and BI grades in patients with periodontitis, and bacterial colonization levels in gingival crevicular fluid and dental plaque in patients with periodontitis at different stages are different. Detection of osclerosin level and identification of periodontal microorganism culture have high clinical value in clinical diagnosis of periodontitis severity and can provide reference for selection of subsequent treatment plan.

[Evaluation of 93 cases of mandibular first molar root bifurcation lesions treated with autologous dentin Granules combined with platelet-rich fibrin membrane].

PURPOSE: To investigate the efficacy of autologous dentin particles combined with platelet-rich fibrin membrane (PRF) in the treatment of root bifurcation lesions of mandibular first molar. METHODS: Ninety-three patients (93 teeth) with mandibular first molar root bifurcation lesions were selected from our department from February 2016 to October 2017. They were randomly divided into 2 groups. Forty-six patients with 46 teeth in the experimental group underwent autologous dentin particles combined with platelet-rich fibrin membrane, while patents in the control group (47 patients with 47 teeth) were treated with Bio-Oss implanted in the bone defect area covered with collagen membrane. The patients were revisted at 1, 3, 6 and 12 months after operation. The success rate of the operation group, the depth of periodontal pocket (PD), the loss of attachment (AL), the depth of penetration of the root bifurcation (HPD), and the bone density of the root bifurcation area before and after treatment. The data were recorded and compared with SPSS25.0 software package. RESULTS: The success rate was 97.83%(45/46) in the experimental group, 85.11%(40/47) in the control group, the difference between the two groups was significant(P<0.05). After treatment, PD, AL and HPD decreased significantly (P<0.05), and MGVs increased gradually. There was no significant difference in MGVs before treatment and 1 month after treatment in the experimental group (P>0.05). MGVs at other time points were significantly higher than those of the control group (P<0.05). PD, AL and HPD of the experimental group were lower significantly than the control group at each time point after treatment (P<0.05), and MGVs value was significantly higher than the control group (P<0.05). There was no significant difference in the incidence of complications(4.35% vs 6.38%, χ2=0.189, P>0.05). CONCLUSIONS: Autologous dentin particles combined with platelet-rich fibrin membrane is effective for the treatment of root bifurcation lesions of mandibular first molar, which is worthy of wide application.

Pancreatic cancer-derived exosomes induce apoptosis of T lymphocytes through the p38 MAPK-mediated endoplasmic reticulum stress.

Pancreatic cancer is the fourth most lethal malignancy and is characterized by poor immunogenicity. Pancreatic cancer cells have various strategies to suppress host immune response, evade immune defenses, and facilitate tumor growth and development. As a mode of long-range intercellular communication, cancer-derived exosomes contribute to impairment of the immune system. However, the mechanisms that induce changes in the activities of signal transduction pathways in immune cells, which are influenced by tumor-derived exosomes, are poorly understood. We (1) treated peripheral T lymphocytes with pancreatic cancer-derived exosomes, tagged CD63 with tdTomato, to trace exosome transfer from pancreatic cancer cells to T lymphocytes; (2) carried out a cytotoxicity assay of exosome-treated T lymphocytes using the Real Time Cellular Analysis system; (3) performed RNA sequencing and gene set enrichment analysis to explore the pivotal signaling pathway that mediates apoptosis in exosome-treated T lymphocytes; and (4) demonstrated the role of p38 mitogen-activated protein kinase (MAPK) and endoplasmic reticulum (ER) stress in exosome-induced T-lymphocyte apoptosis. In conclusion, these results indicate that pancreatic cancer cells secrete exosomes, which are taken up by T lymphocytes to activate p38 MAPK, and then induce ER stress-mediated apoptosis, ultimately causing immunosuppression.

Ultrafast Dynamics of Water-Protein Coupled Motions around the Surface of Eye Crystallin.

Water dynamics on the protein surface mediate both protein structure and function. However, many questions remain about the role of the protein hydration layers in protein fluctuations and how the dynamics of these layers relate to specific protein properties. The fish eye lens protein γM7-crystallin (γM7) is found in vivo at extremely high concentrations nearing the packing limit, corresponding to only a few water layers between adjacent proteins. In this study, we conducted a site-specific probing of hydration water motions and side-chain dynamics at nine selected sites around the surface of γM7 using a tryptophan scan with femtosecond spectroscopy and NMR nuclear spin relaxation (NSR). We observed correlated fluctuations between hydration water and protein side chains on the time scales of a few picoseconds and hundreds of picoseconds, corresponding to local reorientations and network restructuring, respectively. These motions are heterogeneous over the protein surface and relate to the various steric and chemical properties of the local protein environment. Overall, we found that γM7 has relatively slower water dynamics within the hydration shell than a similar ß-sheet protein, which may contribute to the high packing limit of this unique protein.

Solution structure of the nucleotide hydrolase BlsM: Implication of its substrate specificity.

Biosynthesis of the peptidyl nucleoside antifungal agent blasticidin S in Streptomyces griseochromogenes requires the hydrolytic function of a nucleotide hydrolase, BlsM, to excise the free cytosine from the 5'-monophosphate cytosine nucleotide. In addition to its hydrolytic activity, interestingly, BlsM has also been shown to possess a novel cytidine deaminase activity, converting cytidine, and deoxycytidine to uridine and deoxyuridine. To gain insight into the substrate specificity of BlsM and the mechanism by which it performs these dual function, the solution structure of BlsM was determined by multi-dimensional nuclear magnetic resonance approaches. BlsM displays a nucleoside deoxyribosyltransferase-like dimeric topology, with each monomer consisting of a five-stranded ß-sheet that is sandwiched by five α-helixes. Compared with the purine nucleotide hydrolase RCL, each monomer of BlsM has a smaller active site pocket, enclosed by a group of conserved hydrophobic residues from both monomers. The smaller size of active site is consistent with its substrate specificity for a pyrimidine, whereas a much more open active site, as in RCL might be required to accommodate a larger purine ring. In addition, BlsM confers its substrate specificity for a ribosyl-nucleotide through a key residue, Phe19. When mutated to a tyrosine, F19Y reverses its substrate preference. While significantly impaired in its hydrolytic capability, F19Y exhibited a pronounced deaminase activity on CMP, presumably due to an altered substrate orientation as a result of a steric clash between the 2'-hydroxyl of CMP and the ζ-OH group of F19Y. Finally, Glu105 appears to be critical for the dual function of BlsM.

IFN-γ down-regulates the PD-1 expression and assist nivolumab in PD-1-blockade effect on CD8+ T-lymphocytes in pancreatic cancer.

BACKGROUND: Pancreatic cancer is characterized by a highly immunosuppressive tumor microenvironment and evasion of immune surveillance. Although programmed cell death 1 receptor (PD-1) blockade has achieved certain success in immunogenic cancers, the responses to the PD-1 antibody are not effective or sustained in patients with pancreatic cancer. METHODS: Firstly, PD-1 expressions on peripheral CD8+ T-lymphocytes of patients with pancreatic cancer and healthy donors were measured. In in vitro study, peripheral T-lymphocytes were isolated and treated with nivolumab and/or interferon-γ, and next, PD-1-blockade effects, proliferations, cytokine secretions and cytotoxic activities were tested after different treatments. In in vivo study, mice bearing subcutaneous pancreatic cancer cell lines were treated with induced T-lymphocytes and tumor sizes were measured. RESULTS: PD-1 protein expression is increased on peripheral CD8+ T cells in patients with pancreatic ductal adenocarcinoma compared with that in health donor. PD-1 expression on CD8+ T-lymphocytes was decreased by nivolumab in a concentration-dependent manner in vitro. IFN-γ could directly down-regulate expression of PD-1 in vitro. Furthermore, the combination therapy of nivolumab and IFN-γ resulted in greatest effect of PD-1-blockde (1.73 ± 0.78), compared with IFN-γ along (18.63 ± 0.82) and nivolumab along (13.65 ± 1.22). Moreover, the effects of nivolumab plus IFN-γ largest promoted the T-lymphocytes function of proliferations, cytokine secretions and cytotoxic activities. Most importantly, T-lymphocytes induced by nivolumab plus IFN-γ presented the best repression of tumor growth. CONCLUSIONS: IFN-γ plus a PD-1-blockading agent could enhance the immunologic function and might play a crucial role in effective adoptive transfer treatments of pancreatic cancer.

Silencing Of hsa_circ_0008450 Represses Hepatocellular Carcinoma Progression Through Regulation Of microRNA-214-3p/EZH2 Axis.

PURPOSE: Circular RNA (circRNA) hsa_circ_0008450 has been shown to be up-regulated in hepatocellular carcinoma (HCC). However, the functional role of hsa_circ_0008450 and its molecular mechanism are still unknown. PATIENTS AND METHODS: We used qRT-PCR and Western blot to examine the expression levels of hsa_circ_0008450, microRNA-214-3p (miR-214-3p), and enhancer of zeste homolog 2 (EZH2) protein. CCK8 assay and wound healing assay were used to detect cell viability and cell migration capability. Cell apoptosis was assessed by flow cytometry. Luciferase reporter assay was used to explore the interaction among hsa_circ_0008450, miR-214-3p, and EZH2. RESULTS: hsa_circ_0008450 was significantly increased in HCC tissues and cells. Furthermore, knockdown of hsa_circ_0008450 in HCC cells inhibited cell proliferation, invasion, and migration. Mechanically, hsa_circ_0008450 promoted the expression of EZH2 protein through sponging miR-214-3p. Knockdown of circ_0008450 suppressed tumorigenesis of HCC cells in vivo. CONCLUSION: Knockdown of hsa_circ_0008450 inhibits HCC progression by regulating miR-214-3p/EZH2 axis. This study suggests that hsa_circ_0008450 may serve as a novel target for the treatment of HCC.