Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
1.
Org Biomol Chem ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38619101

RESUMO

Thiols and thioesters play crucial roles in pharmaceuticals, biology, and material science as essential organosulfur compounds. Leveraging readily available and cost-effective inert alkanes through direct thioetherification holds promise for yielding high-value-added products. Herein, we present a photoinduced strategy for sulfur-containing modification of inert alkanes utilizing decatungstate as hydrogen atom transfer reagent, offering a straightforward and practical approach for synthesizing thioethers and thioesters.

2.
Ann Surg Oncol ; 31(2): 872-882, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37962740

RESUMO

BACKGROUND: This study aimed to evaluate the dynamic impact of the micropapillary (MIP) component on local recurrence (LR), distant metastasis (DM), and multiple recurrence (MR) of pathological stage IA3 lung adenocarcinoma. METHODS: Between July 2012 and July 2020, a total of 351 patients at two medical institutions were enrolled in this study. Cumulative incidence of curves, dynamic risk curves, and time-dependent multivariate analysis was performed to evaluate the effect of the MIP component on patients. RESULTS: The 5-year cumulative incidence of total recurrence with or without an MIP component was 34.2% and 12.3%, respectively (p = 0.001). In three recurrence patterns, our findings revealed that the 5-year cumulative incidence of LR (p = 0.048) and DM (p = 0.005) was higher in the 'MIP-present' group than in the 'MIP-absent' group. In the dynamic recurrence curve, the risk of the three recurrence patterns was different and varied over time between the two groups, especially in DM. Moreover, the dynamic cumulative event curve showed that after 1, 2, and 3 years of survival, the cumulative incidence of DM in the group with MIP continued to be higher than that in the group without MIP (all p < 0.05). Time-dependent Cox regression analysis indicated that the MIP component continued to be an independent risk factor for the cumulative incidence of DM in patients with 3-year survival. CONCLUSIONS: Of the three recurrence patterns, the MIP component mainly aggravated the risk of DM in patients with pathological stage IA3 lung adenocarcinoma, which persisted for 3 years.


Assuntos
Adenocarcinoma de Pulmão , Adenocarcinoma , Neoplasias Pulmonares , Humanos , Estudos Retrospectivos , Neoplasias Pulmonares/patologia , Adenocarcinoma/cirurgia , Adenocarcinoma/patologia , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/cirurgia , Recidiva Local de Neoplasia/patologia , Adenocarcinoma de Pulmão/patologia , Prognóstico
4.
Cell Death Dis ; 14(12): 799, 2023 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-38057328

RESUMO

HSP90 has emerged as an appealing anti-cancer target. However, HSP90 inhibitors (HSP90i) are characterized by limited clinical utility, primarily due to the resistance acquisition via heat shock response (HSR) induction. Understanding the roles of abundantly expressed cytosolic HSP90 isoforms (α and ß) in sustaining malignant cells' growth and the mechanisms of resistance to HSP90i is crucial for exploiting their clinical potential. Utilizing multi-omics approaches, we identified that ablation of the HSP90ß isoform induces the overexpression of HSP90α and extracellular-secreted HSP90α (eHSP90α). Notably, we found that the absence of HSP90α causes downregulation of PTPRC (or CD45) expression and restricts in vivo growth of BCR-ABL1+ leukemia cells. Subsequently, chronic long-term exposure to the clinically advanced HSP90i PU-H71 (Zelavespib) led to copy number gain and mutation (p.S164F) of the HSP90AA1 gene, and HSP90α overexpression. In contrast, acquired resistance toward other tested HSP90i (Tanespimycin and Coumermycin A1) was attained by MDR1 efflux pump overexpression. Remarkably, combined CDK7 and HSP90 inhibition display synergistic activity against therapy-resistant BCR-ABL1+ patient leukemia cells via blocking pro-survival HSR and HSP90α overexpression, providing a novel strategy to avoid the emergence of resistance against treatment with HSP90i alone.


Assuntos
Antineoplásicos , Proteínas de Choque Térmico HSP90 , Leucemia , Neoplasias , Humanos , Antineoplásicos/farmacologia , Proteínas de Choque Térmico HSP90/metabolismo , Leucemia/tratamento farmacológico , Leucemia/genética , Mutação , Resistencia a Medicamentos Antineoplásicos
5.
Insights Imaging ; 14(1): 222, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38117404

RESUMO

OBJECTIVES: Precise determination of cervical lymph node metastasis (CLNM) involvement in patients with early-stage thyroid cancer is fairly significant for identifying appropriate cervical treatment options. However, it is almost impossible to directly judge lymph node metastasis based on the imaging information of early-stage thyroid cancer patients with clinically negative lymph nodes. METHODS: Preoperative US images (BMUS and CDFI) of 1031 clinically node negative PTC patients definitively diagnosed on pathology from two independent hospitals were divided into training set, validation set, internal test set, and external test set. An ensemble deep learning model based on ResNet-50 was built integrating clinical variables, BMUS, and CDFI images using a bagging classifier to predict metastasis of CLN. The final ensemble model performance was compared with expert interpretation. RESULTS: The ensemble deep convolutional neural network (DCNN) achieved high performance in predicting CLNM in the test sets examined, with area under the curve values of 0.86 (95% CI 0.78-0.94) for the internal test set and 0.77 (95% CI 0.68-0.87) for the external test set. Compared to all radiologists averaged, the ensemble DCNN model also exhibited improved performance in making predictions. For the external validation set, accuracy was 0.72 versus 0.59 (p = 0.074), sensitivity was 0.75 versus 0.58 (p = 0.039), and specificity was 0.69 versus 0.60 (p = 0.078). CONCLUSIONS: Deep learning can non-invasive predict CLNM for clinically node-negative PTC using conventional US imaging of thyroid cancer nodules and clinical variables in a multi-institutional dataset with superior accuracy, sensitivity, and specificity comparable to experts. CRITICAL RELEVANCE STATEMENT: Deep learning efficiently predicts CLNM for clinically node-negative PTC based on US images and clinical variables in an advantageous manner. KEY POINTS: • A deep learning-based ensemble algorithm for predicting CLNM in PTC was developed. • Ultrasound AI analysis combined with clinical data has advantages in predicting CLNM. • Compared to all experts averaged, the DCNN model achieved higher test performance.

6.
Nat Commun ; 14(1): 6530, 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37845202

RESUMO

Organoboron compounds are of high significance in organic synthesis due to the unique versatility of boryl substituents to access further modifications. The high demand for the incorporation of boryl moieties into molecular structures has witnessed significant progress, particularly in the C(sp3)-H borylation of hydrocarbons. Taking advantage of special characteristics of photo/electrochemistry, we herein describe the development of an oxidative C(sp3)-H borylation reaction under metal- and oxidant-free conditions, enabled by photoelectrochemical strategy. The reaction exhibits broad substrate scope (>57 examples), and includes the use of simple alkanes, halides, silanes, ketones, esters and nitriles as viable substrates. Notably, unconventional regioselectivity of C(sp3)-H borylation is achieved, with the coupling site of C(sp3)-H borylation selectively located in the distal methyl group. Our method is operationally simple and easily scalable, and offers a feasible approach for the one-step synthesis of high-value organoboron building blocks from simple hydrocarbons, which would provide ample opportunities for drug discovery.

7.
Proc Natl Acad Sci U S A ; 120(44): e2310174120, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37883437

RESUMO

α-synuclein (α-Syn) is a presynaptic protein that is involved in Parkinson's and other neurodegenerative diseases and binds to negatively charged phospholipids. Previously, we reported that α-Syn clusters synthetic proteoliposomes that mimic synaptic vesicles. This vesicle-clustering activity depends on a specific interaction of α-Syn with anionic phospholipids. Here, we report that α-Syn surprisingly also interacts with the neutral phospholipid lysophosphatidylcholine (lysoPC). Even in the absence of anionic lipids, lysoPC facilitates α-Syn-induced vesicle clustering but has no effect on Ca2+-triggered fusion in a single vesicle-vesicle fusion assay. The A30P mutant of α-Syn that causes familial Parkinson disease has a reduced affinity to lysoPC and does not induce vesicle clustering. Taken together, the α-Syn-lysoPC interaction may play a role in α-Syn function.


Assuntos
Doença de Parkinson , alfa-Sinucleína , Humanos , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Vesículas Sinápticas/metabolismo , Lisofosfatidilcolinas/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Fosfolipídeos/metabolismo
8.
Int J Colorectal Dis ; 38(1): 243, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37779168

RESUMO

PURPOSE: The present study aims to determine the rectoanal colonization rate and risk factors for the colonization of present multidrug-resistant bacteria (MDRBs). In addition, the relationship between MDRB colonization and surgical site infection (SSI) following hemorrhoidectomy was explored. METHODS: A cross-sectional study was conducted in the Department of Colorectal Surgery of two hospitals. Patients with hemorrhoid disease, who underwent hemorrhoidectomy, were included. The pre-surgical screening of multidrug-resistant Gram-negative bacteria (MDR-GNB) colonization was performed using rectal swabs on the day of admission. Then, the MDRB colonization rate was determined through the rectal swab. Logistic regression models were established to determine the risk factors for MDRB colonization and SSI after hemorrhoidectomy. A p-value of < 0.05 was considered statistically significant. RESULTS: A total of 432 patients met the inclusion criteria, and the MDRB colonization prevalence was 21.06% (91/432). The independent risk factors for MDRB colonization were as follows: patients who received ≥ 2 categories of antibiotic treatment within 3 months (odds ratio (OR): 3.714, 95% confidence interval (CI): 1.436-9.605, p = 0.007), patients with inflammatory bowel disease (IBD; OR: 6.746, 95% CI: 2.361-19.608, p < 0.001), and patients with high serum uric acid (OR: 1.006, 95% CI: 1.001-1.010, p = 0.017). Furthermore, 41.57% (37/89) of MDRB carriers and 1.81% (6/332) of non-carriers developed SSIs, with a total incidence of 10.21% (43/421). Based on the multivariable model, the rectoanal colonization of MDRBs (OR: 32.087, 95% CI: 12.052-85.424, p < 0.001) and hemoglobin < 100 g/L (OR: 4.130, 95% CI: 1.556-10.960, p = 0.004) were independently associated with SSI after hemorrhoidectomy. CONCLUSION: The rectoanal colonization rate of MDRBs in hemorrhoid patients is high, and this was identified as an independent risk factor for SSI after hemorrhoidectomy.


Assuntos
Infecções Bacterianas , Hemorroidectomia , Hemorroidas , Humanos , Infecções Bacterianas/microbiologia , Estudos Transversais , Hemorroidectomia/efeitos adversos , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/tratamento farmacológico , Hemorroidas/cirurgia , Hemorroidas/tratamento farmacológico , Ácido Úrico , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Fatores de Risco , Bactérias Gram-Negativas
9.
Int J Mol Sci ; 24(19)2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37834300

RESUMO

Food-derived peptides have good antioxidant activity and are highly safe for humans; consequently, there has been continuous growth in research on antioxidants, with potential applications in food, medicine, cosmetics, and other fields. Among food-derived peptides, walnut-derived peptides have attracted increasing attention as food-derived peptides rich in eight essential amino acids. This review summarizes the progress made in the development and identification of antioxidant peptides in walnut proteins. This article mainly describes the interaction between reactive oxygen species and cellular antioxidant products, modulation of enzyme content and activity, and regulation of the redox signaling pathways and analyzes the mechanisms of reduction in oxidative stress. Finally, the complex structure-activity relationships of walnut-derived peptides are analyzed based on their amino acid composition and secondary structure of the polypeptides. This review provides a theoretical basis for the production of walnut-derived antioxidant peptides and could help promote the development of the walnut industry.


Assuntos
Antioxidantes , Juglans , Humanos , Antioxidantes/química , Juglans/química , Nozes/química , Estresse Oxidativo , Peptídeos/química
10.
Int J Biol Macromol ; 253(Pt 6): 127347, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37820898

RESUMO

Transforming waste into resources is an important strategy to enhance the economic efficiency and reduce the waste entering the environment. In this work, iron-loading N and S co-doped porous carbon materials, as peroxymonosulfate (PMS) activator for pollutants degradation, were prepared by pyrolysis of the mixture of iron loading chitosan and CdS-Tetrahymena thermophila under N2 flow. Chitosan is mainly derived from the shell waste of shrimp and crab, and CdS-Tetrahymena thermophila is produced in the removing process of Cd2+ pollution bioremediation using Tetrahymena thermophila. The synergistic effects of iron related species and heteroatoms (S/N) co-doped porous carbon in the obtained carbon materials improved the performance for activating PMS. The prepared Fe-S-CS-1-900 exhibited high performance for the degradation of Rhodamine B (RhB) by activating PMS. Radical quenching tests and electron paramagnetic resonance measurements suggested that superoxide radical (O2-) and singlet oxygen (1O2) were the primary reactive oxygen species in RhB degradation. These results propose new insights of using biomass waste to derive Fe-loading N and S heteroatom co-doping carbon as PMS activator applied in the removal of organic pollutants.


Assuntos
Quitosana , Poluentes Ambientais , Tetrahymena thermophila , Ferro , Carbono , Porosidade
11.
Biochem Pharmacol ; 217: 115809, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37717691

RESUMO

Although a great cure rate has been achieved for pediatric BCP-ALL, approximately 15% of patients do not respond to conventional chemotherapy and experience disease relapse. A major effort to improve the cure rates by treatment intensification would result in an undesirable increase in treatment-related toxicity and mortality, raising the need to identify novel therapeutic approaches. High-throughput (HTP) drug screening enables the profiling of patients' responses in vitro and allows the repurposing of compounds currently used for other diseases, which can be immediately available for clinical application. The aim of this study was to apply HTP drug screening to identify potentially effective compounds for the treatment of pediatric BCP-ALL patients with poor prognosis, such as patients with Down Syndrome (DS) or carrying rearrangements involving PAX5 or KMT2A/MLL genes. Patient-derived Xenografts (PDX) samples from 34 BCP-ALL patients (9 DS CRLF2r, 15 PAX5r, 10 MLLr), 7 human BCP-ALL cell lines and 14 hematopoietic healthy donor samples were screened on a semi-automated HTP drug screening platform using a 174 compound library (FDA/EMA-approved or in preclinical studies). We identified 9 compounds active against BCP-ALL (ABT-199/venetoclax, AUY922/luminespib, dexamethasone, EC144, JQ1, NVP-HSP990, paclitaxel, PF-04929113 and vincristine), but sparing normal cells. Ex vivo validations confirmed that the BCL2 inhibitor venetoclax exerts an anti-leukemic effect against all three ALL subgroups at nanomolar concentrations. Overall, this study points out the benefit of HTP screening application for drug repurposing to allow the identification of effective and clinically translatable therapeutic agents for difficult-to-treat childhood BCP-ALL subgroups.


Assuntos
Reposicionamento de Medicamentos , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Humanos , Criança , Ensaios de Triagem em Larga Escala , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico
12.
Transl Lung Cancer Res ; 12(5): 1078-1092, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37323166

RESUMO

Background: This study aimed to evaluate the effect of the presence of a radiographically manifested ground-glass opacity (GGO) component on the prognosis of patients with pathological stage IA3 lung adenocarcinoma. Methods: Patients diagnosed with pathological stage IA3 lung adenocarcinoma who underwent radical surgery at two medical institutions in China between July 2012 and July 2020 were enrolled. The cumulative incidence of recurrence (CIR) and cumulative incidence of death (CID) in patients with and without a GGO component were compared. Risk curves for the recurrence and tumor-related death overtime were analyzed between the two groups according to life table. In order to validate the prognostic value of GGO components, the recurrence-free survival (RFS) and cancer-specific survival (CSS) were estimated. Decision curve analysis (DCA) was performed to evaluate the clinical benefit rate of different models. Results: Among the 352 included patients, the presence of a GGO component was radiographically shown in 166 (47.2%) patients, while 186 (52.8%) displayed solid nodules. Patients exhibiting the absence of a GGO component had higher incidences of total recurrence (17.2% vs. 3.0%, P<0.001), local-regional recurrence (LRR) (5.4% vs. 0.6%, P=0.010), distant metastasis (DM) (8.1% vs. 1.8%, P=0.008), and multiple recurrences (4.3% vs. 0.6%, P=0.028) than the presence-GGO component group. The 5-year CIR and CID were 7.5% and 7.4% in the presence-GGO component group, and 24.5% and 17.0% in the absence-GGO component group, respectively, with statistically significant differences between the two groups (P<0.05). The risk of recurrence in patients with the presence of GGO components showed a single peak at 3 years postoperatively, while patients with the absence of GGO components showed a double peak at 1 and 5 years after surgery, respectively. However, the risk of tumor-related death peaked in both groups at 3 and 6 years postoperatively. Multivariate Cox analysis showed that the presence of a GGO component was a favorable independent risk factor for pathological stage IA3 lung adenocarcinoma patients (P<0.05). Conclusions: Pathological stage IA3 lung adenocarcinoma with or without GGO components are two types of tumors with different invasive abilities. In clinical practice, we should develop different treatment and follow-up strategies.

14.
BMC Geriatr ; 23(1): 340, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-37259039

RESUMO

BACKGROUND: This study systematically reviewed injury death and causes in the elderly population in China from 2000 to 2020, to prevent or reduce the occurrence of injuries and death. METHODS: The CNKI, VIP, Wan Fang, MEDLINE, Embase, SinoMed, and Web of Science databases were searched to collect epidemiological characteristics of injury death among elderly over 60 years old in China from January 2000 to December 2020. Random effects meta-analysis was performed to pool injury mortality rate and identify publication bias, with study quality assessed using the AHRQ risk of bias tool. RESULTS: (1) A total of 41 studies with 187 488 subjects were included, covering 125 million elderly. The pooled injury mortality rate was 135.58/105 [95%CI: (113.36 to 162.14)/105], ranking second in the total death cause of the elderly. (2)Subgroup analysis showed that male injury death (146.00/105) was significantly higher than that of females (127.90/105), and overall injury mortality increased exponentially with age (R2 = 0.957), especially in those over 80 years old; the spatial distribution shows that the injury death rate in the central region is higher than that in the east and west and that in the countryside is higher than that in the city; the distribution of death time shows that after entering an aging society (2000-2020) is significantly higher than before (1990-2000). (3) There are more than 12 types of injury death, and the top three are falling, traffic accidents, and suicide. CONCLUSIONS: China's elderly injury death rate is at a high level in the world, with more males than females, especially after the age of 80. There are regional differences. The main types of injury death are falling, traffic, and suicide. During the 14th Five-Year Plan period, for accidental injuries and death, a rectification list for aging and barrier-free environments was issued. PROSPERO REGISTRATION: The systematic review was registered in PROSPERO under protocol number CRD42022359992.


Assuntos
Acidentes por Quedas , Acidentes de Trânsito , Big Data , População do Leste Asiático , Suicídio Consumado , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Acidentes de Trânsito/mortalidade , China/epidemiologia , Prevalência , Acidentes por Quedas/mortalidade
15.
Ann Surg Oncol ; 30(9): 5843-5853, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37219654

RESUMO

INTRODUCTION: The study investigated the synergistic effect of the micropapillary (MIP) component and consolidation-to-tumor ratio (CTR) on the recurrence and survival of patients with pathologic stage IA3 lung adenocarcinoma. METHODS: We enrolled 419 patients confirmed pathological stage IA3 adenocarcinoma from four institutions. Kaplan-Meier analysis was performed to examine the value of the MIP component and CTR on relapse-free survival (RFS) and overall survival (OS). The cumulative recurrence between different stages was analyzed by using cumulative event curves. RESULTS: RFS (P < 0.0001) and OS (P = 0.008) in the presence of the MIP group were significantly lower than those in the absence of the MIP group, and CTR > 5 only reduced RFS (P = 0.0004), but not OS (P = 0.063), in the patients. In addition, the prognosis of patients with both the MIP component and CTR > 5 was worse than that of those without the MIP component or CTR ≤ 5. Therefore, we established new subtypes of the stage IA3: IA3a, IA3b, and IA3c. RFS and OS for IA3c staging were significantly lower than those for IA3a and IA3b. For IA3c, the cumulative incidence of local recurrence (P < 0.001) and that of distant metastasis (P = 0.004) were significantly higher than those for IA3a and IA3b. CONCLUSIONS: The MIP component combined with CTR > 0.5 can effectively predict the prognosis of patients with pathological stage IA3 lung adenocarcinoma and may offer more detailed recurrence and survival information according to the established subtype stage of IA3.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/patologia , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/cirurgia , Recidiva Local de Neoplasia/patologia , Adenocarcinoma de Pulmão/patologia , Prognóstico , Estudos Retrospectivos
16.
Sci Rep ; 13(1): 8271, 2023 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-37217571

RESUMO

Peri-implantitis is a common complication characterized by inflammation in tissues surrounding dental implants due to plaque accumulation, which can lead to implant failure. While air flow abrasive treatment has been found to be effective for debriding implant surfaces, little is known about the factors that affect its cleaning capacity. This study systematically examined the cleaning capacity of air powder abrasive (APA) treatment with ß-tricalcium phosphate (ß-TCP) powder, using various powder jetting strengths and different particle sizes. Three sizes of ß-TCP powder (S, M, and L) were prepared, and different powder settings (low, medium, and high) were tested. The cleaning capacity was determined by quantifying ink removal, which simulated biofilm removal from the implant surfaces at different time points. The results of the systematic comparisons showed that the most efficient cleaning of implant surfaces was achieved using size M particles with medium setting. Additionally, the amount of powder consumed was found to be critical to cleaning efficiency, and the implant surfaces were altered in all tested groups. These systematically analyzed outcomes may provide insights into the development of potential non-surgical strategies for treating peri-implant diseases.


Assuntos
Implantes Dentários , Peri-Implantite , Humanos , Pós , Desbridamento , Propriedades de Superfície , Peri-Implantite/terapia
17.
J Am Chem Soc ; 145(13): 7600-7611, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-36958308

RESUMO

Catalytic C(sp3)-H functionalization has provided enormous opportunities to construct organic molecules, facilitating the derivatization of complex pharmaceutical compounds. Within this framework, direct hydrogen atom transfer (HAT) photocatalysis becomes an appealing approach to this goal. However, the viable substrates utilized in these protocols are limited, and the site selectivity shows preference to activated and thermodynamically favored C(sp3)-H bonds. Herein, we describe the development of undirected iron-catalyzed C(sp3)-H borylation, thiolation, and sulfinylation reactions enabled by the photoinduced ligand-to-metal charge transfer (LMCT) process. These reactions exhibit remarkably broad substrate scope (>150 examples in total), and most importantly, all of these three reactions show unconventional regioselectivity, with the occurrence of C(sp3)-H borylation, thiolation, and sulfinylation preferentially at the distal methyl position. The procedures are operationally simple and readily scalable and provide access to high-value products from simple hydrocarbons in one step. Mechanistic studies and control experiments indicate that the afforded site selectivity is not only relevant to the HAT species but also largely affected by the use of boron- and sulfone-based radical acceptors.

18.
Bioinformatics ; 39(1)2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36610709

RESUMO

MOTIVATION: Spatially resolved gene expression profiles are the key to exploring the cell type spatial distributions and understanding the architecture of tissues. Many spatially resolved transcriptomics (SRT) techniques do not provide single-cell resolutions, but they measure gene expression profiles on captured locations (spots) instead, which are mixtures of potentially heterogeneous cell types. Currently, several cell-type deconvolution methods have been proposed to deconvolute SRT data. Due to the different model strategies of these methods, their deconvolution results also vary. RESULTS: Leveraging the strengths of multiple deconvolution methods, we introduce a new weighted ensemble learning deconvolution method, EnDecon, to predict cell-type compositions on SRT data in this work. EnDecon integrates multiple base deconvolution results using a weighted optimization model to generate a more accurate result. Simulation studies demonstrate that EnDecon outperforms the competing methods and the learned weights assigned to base deconvolution methods have high positive correlations with the performances of these base methods. Applied to real datasets from different spatial techniques, EnDecon identifies multiple cell types on spots, localizes these cell types to specific spatial regions and distinguishes distinct spatial colocalization and enrichment patterns, providing valuable insights into spatial heterogeneity and regionalization of tissues. AVAILABILITY AND IMPLEMENTATION: The source code is available at https://github.com/Zhangxf-ccnu/EnDecon. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Perfilação da Expressão Gênica , Transcriptoma , Software , Simulação por Computador , Aprendizado de Máquina
19.
Environ Toxicol ; 38(1): 90-100, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36176197

RESUMO

Temozolomide (TMZ) can cross the blood-brain barrier (BBB) and deliver methyl groups to the purine (guanine) bases of DNA, leading to mispairing during DNA replication and subsequent cell death. However, increased expression of the repair enzyme methyl guanine methyltransferase (MGMT), which removes methyl groups from purine bases, counteracts methylation by TMZ. We evaluated the anticancer potential of thymoquinone (TQ), a hydrophobic flavonoid that inhibits resistance and induces apoptosis in various cancer cells, both in vitro and in vivo. In vitro experiments showed that compared with the Hs683 and M059J cell lines, U251 cells were more sensitive to TMZ. Compared to U251 cells, U251R cells, a TMZ drug-resistant strain established in this study, are characterized by increased expression of phosphorylated extracellular signal-regulated kinase (p-ERK) and MGMT. TQ treatments induced apoptosis in all cell lines. The p38 mitogen-activated protein kinase signal pathway was mainly activated in U251 and U251R cells; however, p-ERK and MGMT upregulation could not suppress TQ effects. Furthermore, si-p38 pretreatment of U251R cells in TQ treatments inhibited cell apoptosis. We speculate that TQ contributed to the phosphorylation and activation of p38, but not of ERK-induced apoptosis (irrespective of TMZ resistance). In vivo, U251R-derived tumors subcutaneously inoculated in nude mice exhibited significant tumor volume reduction after TQ or TQ + TMZ cotreatments. High-performance liquid chromatography assay confirmed the presence of TQ in murine brain tissues. Our findings demonstrate that TQ can effectively cross the BBB and function alone or in combination with TMZ to treat glioblastoma.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Camundongos , Animais , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Glioblastoma/patologia , Dacarbazina/farmacologia , Dacarbazina/uso terapêutico , Camundongos Nus , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Apoptose , Transdução de Sinais , Purinas/farmacologia , Purinas/uso terapêutico , Guanina/farmacologia , Guanina/uso terapêutico , Antineoplásicos Alquilantes/farmacologia , Neoplasias Encefálicas/metabolismo
20.
Eur J Med Chem ; 246: 114944, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36459756

RESUMO

The homologous recombination repair (HRR) pathway is critical for repairing double-strand breaks (DSB). Inhibition of the HRR pathway is usually considered a promising strategy for anticancer therapy. The Bloom's Syndrome Protein (BLM), a DNA helicase, is essential for promoting the HRR pathway. Previously, we discovered quinazolinone derivative 9h as a potential BLM inhibitor, which suppressed the proliferation of colorectal cancer (CRC) cell HCT116. Herein, a new series of quinazolinone derivatives with N3-substitution was designed and synthesized to improve the anticancer activity and explore the structure-activity relationship (SAR). After evaluating their BLM inhibitory activity, the SAR was discussed, leading to identifying compound 21 as a promising BLM inhibitor. 21 exhibited the potent BLM-dependent cytotoxicity against the CRC cells but weak against normal cells. Further evaluation revealed that 21 could disrupt the HRR level while inhibiting BLM located on the DSB site and trigger DNA damage in the CRC cells. This compound effectively suppressed the proliferation and invasion of CRC cells, along with cell cycle arrest and apoptosis. Consequently, 21 might be a promising candidate for treating CRC, and the BLM might be a new potential therapeutic target for CRC.


Assuntos
Síndrome de Bloom , Neoplasias Colorretais , Humanos , Síndrome de Bloom/genética , Quinazolinonas/farmacologia , Reparo do DNA , Dano ao DNA , Neoplasias Colorretais/tratamento farmacológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...