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1.
Brief Bioinform ; 24(1)2023 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-36562719

RESUMEN

BACKGROUND: Cell-penetrating peptides (CPPs) have received considerable attention as a means of transporting pharmacologically active molecules into living cells without damaging the cell membrane, and thus hold great promise as future therapeutics. Recently, several machine learning-based algorithms have been proposed for predicting CPPs. However, most existing predictive methods do not consider the agreement (disagreement) between similar (dissimilar) CPPs and depend heavily on expert knowledge-based handcrafted features. RESULTS: In this study, we present SiameseCPP, a novel deep learning framework for automated CPPs prediction. SiameseCPP learns discriminative representations of CPPs based on a well-pretrained model and a Siamese neural network consisting of a transformer and gated recurrent units. Contrastive learning is used for the first time to build a CPP predictive model. Comprehensive experiments demonstrate that our proposed SiameseCPP is superior to existing baseline models for predicting CPPs. Moreover, SiameseCPP also achieves good performance on other functional peptide datasets, exhibiting satisfactory generalization ability.


Asunto(s)
Péptidos de Penetración Celular , Péptidos de Penetración Celular/metabolismo , Algoritmos , Transporte Biológico , Redes Neurales de la Computación , Aprendizaje Automático
2.
Bioinformatics ; 40(5)2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38696758

RESUMEN

MOTIVATION: Peptides are promising agents for the treatment of a variety of diseases due to their specificity and efficacy. However, the development of peptide-based drugs is often hindered by the potential toxicity of peptides, which poses a significant barrier to their clinical application. Traditional experimental methods for evaluating peptide toxicity are time-consuming and costly, making the development process inefficient. Therefore, there is an urgent need for computational tools specifically designed to predict peptide toxicity accurately and rapidly, facilitating the identification of safe peptide candidates for drug development. RESULTS: We provide here a novel computational approach, CAPTP, which leverages the power of convolutional and self-attention to enhance the prediction of peptide toxicity from amino acid sequences. CAPTP demonstrates outstanding performance, achieving a Matthews correlation coefficient of approximately 0.82 in both cross-validation settings and on independent test datasets. This performance surpasses that of existing state-of-the-art peptide toxicity predictors. Importantly, CAPTP maintains its robustness and generalizability even when dealing with data imbalances. Further analysis by CAPTP reveals that certain sequential patterns, particularly in the head and central regions of peptides, are crucial in determining their toxicity. This insight can significantly inform and guide the design of safer peptide drugs. AVAILABILITY AND IMPLEMENTATION: The source code for CAPTP is freely available at https://github.com/jiaoshihu/CAPTP.


Asunto(s)
Biología Computacional , Péptidos , Péptidos/química , Biología Computacional/métodos , Humanos , Secuencia de Aminoácidos , Algoritmos , Programas Informáticos
3.
Brief Bioinform ; 23(3)2022 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-35262678

RESUMEN

Accurate prediction of drug-target interactions (DTIs) can reduce the cost and time of drug repositioning and drug discovery. Many current methods integrate information from multiple data sources of drug and target to improve DTIs prediction accuracy. However, these methods do not consider the complex relationship between different data sources. In this study, we propose a novel computational framework, called MccDTI, to predict the potential DTIs by multiview network embedding, which can integrate the heterogenous information of drug and target. MccDTI learns high-quality low-dimensional representations of drug and target by preserving the consistent and complementary information between multiview networks. Then MccDTI adopts matrix completion scheme for DTIs prediction based on drug and target representations. Experimental results on two datasets show that the prediction accuracy of MccDTI outperforms four state-of-the-art methods for DTIs prediction. Moreover, literature verification for DTIs prediction shows that MccDTI can predict the reliable potential DTIs. These results indicate that MccDTI can provide a powerful tool to predict new DTIs and accelerate drug discovery. The code and data are available at: https://github.com/ShangCS/MccDTI.


Asunto(s)
Desarrollo de Medicamentos , Reposicionamiento de Medicamentos , Descubrimiento de Drogas , Interacciones Farmacológicas
4.
Brief Bioinform ; 23(5)2022 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-36070864

RESUMEN

The location of microRNAs (miRNAs) in cells determines their function in regulation activity. Studies have shown that miRNAs are stable in the extracellular environment that mediates cell-to-cell communication and are located in the intracellular region that responds to cellular stress and environmental stimuli. Though in situ detection techniques of miRNAs have made great contributions to the study of the localization and distribution of miRNAs, miRNA subcellular localization and their role are still in progress. Recently, some machine learning-based algorithms have been designed for miRNA subcellular location prediction, but their performance is still far from satisfactory. Here, we present a new data partitioning strategy that categorizes functionally similar locations for the precise and instructive prediction of miRNA subcellular location in Homo sapiens. To characterize the localization signals, we adopted one-hot encoding with post padding to represent the whole miRNA sequences, and proposed a deep bidirectional long short-term memory with the multi-head self-attention algorithm to model. The algorithm showed high selectivity in distinguishing extracellular miRNAs from intracellular miRNAs. Moreover, a series of motif analyses were performed to explore the mechanism of miRNA subcellular localization. To improve the convenience of the model, a user-friendly web server named iLoc-miRNA was established (http://iLoc-miRNA.lin-group.cn/).


Asunto(s)
Biología Computacional , MicroARNs , Algoritmos , Biología Computacional/métodos , Humanos , Aprendizaje Automático , MicroARNs/genética
5.
Bioinformatics ; 39(11)2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37847658

RESUMEN

MOTIVATION: The rapid and extensive transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented global health emergency, affecting millions of people and causing an immense socioeconomic impact. The identification of SARS-CoV-2 phosphorylation sites plays an important role in unraveling the complex molecular mechanisms behind infection and the resulting alterations in host cell pathways. However, currently available prediction tools for identifying these sites lack accuracy and efficiency. RESULTS: In this study, we presented a comprehensive biological function analysis of SARS-CoV-2 infection in a clonal human lung epithelial A549 cell, revealing dramatic changes in protein phosphorylation pathways in host cells. Moreover, a novel deep learning predictor called PSPred-ALE is specifically designed to identify phosphorylation sites in human host cells that are infected with SARS-CoV-2. The key idea of PSPred-ALE lies in the use of a self-adaptive learning embedding algorithm, which enables the automatic extraction of context sequential features from protein sequences. In addition, the tool uses multihead attention module that enables the capturing of global information, further improving the accuracy of predictions. Comparative analysis of features demonstrated that the self-adaptive learning embedding features are superior to hand-crafted statistical features in capturing discriminative sequence information. Benchmarking comparison shows that PSPred-ALE outperforms the state-of-the-art prediction tools and achieves robust performance. Therefore, the proposed model can effectively identify phosphorylation sites assistant the biomedical scientists in understanding the mechanism of phosphorylation in SARS-CoV-2 infection. AVAILABILITY AND IMPLEMENTATION: PSPred-ALE is available at https://github.com/jiaoshihu/PSPred-ALE and Zenodo (https://doi.org/10.5281/zenodo.8330277).


Asunto(s)
COVID-19 , Redes Neurales de la Computación , Humanos , SARS-CoV-2 , Fosforilación , Algoritmos
6.
Methods ; 211: 61-67, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36804215

RESUMEN

Recent advances in multi-omics databases offer the opportunity to explore complex systems of cancers across hierarchical biological levels. Some methods have been proposed to identify the genes that play a vital role in disease development by integrating multi-omics. However, the existing methods identify the related genes separately, neglecting the gene interactions that are related to the multigenic disease. In this study, we develop a learning framework to identify the interactive genes based on multi-omics data including gene expression. Firstly, we integrate different omics based on their similarities and apply spectral clustering for cancer subtype identification. Then, a gene co-expression network is construct for each cancer subtype. Finally, we detect the interactive genes in the co-expression network by learning the dense subgraphs based on the L1 prosperities of eigenvectors in the modularity matrix. We apply the proposed learning framework on a multi-omics cancer dataset to identify the interactive genes for each cancer subtype. The detected genes are examined by DAVID and KEGG tools for systematic gene ontology enrichment analysis. The analysis results show that the detected genes have relationships to cancer development and the genes in different cancer subtypes are related to different biological processes and pathways, which are expected to yield important references for understanding tumor heterogeneity and improving patient survival.


Asunto(s)
Multiómica , Neoplasias , Humanos , Neoplasias/genética , Análisis por Conglomerados , Bases de Datos Factuales
7.
Methods ; 219: 1-7, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37689121

RESUMEN

With the increasing availability of large-scale QSAR (Quantitative Structure-Activity Relationship) datasets, collaborative analysis has become a promising approach for drug discovery. Traditional centralized analysis which typically concentrates data on a central server for training faces challenges such as data privacy and security. Distributed analysis such as federated learning offers a solution by enabling collaborative model training without sharing raw data. However, it may fail when the training data in the local devices are non-independent and identically distributed (non-IID). In this paper, we propose a novel framework for collaborative drug discovery using federated learning on non-IID datasets. We address the difficulty of training on non-IID data by globally sharing a small subset of data among all institutions. Our framework allows multiple institutions to jointly train a robust predictive model while preserving the privacy of their individual data. We leverage the federated learning paradigm to distribute the model training process across local devices, eliminating the need for data exchange. The experimental results on 15 benchmark datasets demonstrate that the proposed method achieves competitive predictive accuracy to centralized analysis while respecting data privacy. Moreover, our framework offers benefits such as reduced data transmission and enhanced scalability, making it suitable for large-scale collaborative drug discovery efforts.


Asunto(s)
Benchmarking , Descubrimiento de Drogas
8.
Phys Chem Chem Phys ; 26(15): 11657-11666, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38563149

RESUMEN

Silica exhibits a rich phase diagram with numerous stable structures existing at different temperature and pressure conditions, including its glassy form. In large-scale atomistic simulations, due to the small energy difference, several phases may coexist. While, in terms of long-range order, there are clear differences between these phases, their short- or medium-range structural properties are similar for many phases, thus making it difficult to detect the structural differences. In this study, a methodology based on unsupervised learning is proposed to detect the differences in local structures between eight phases of silica, using atomic models prepared by molecular dynamics (MD) simulations. A combination of two-step locality preserving projections (TS-LPP) and locally averaged atomic fingerprints (LAAF) descriptor was employed to find a low-dimensional space in which the differences among all the phases can be detected. From the distance between each structure in the found low-dimensional space, the similarity between the structures can be discussed and subtle local changes in the structures can be detected. Using the obtained low-dimensional space, the ß-α transition in quartz at a low temperature was analyzed, as well as the structural evolution during the melt-quench process starting from α-quartz. The proper differentiation and ease of visualization make the present methodology promising for improving the analysis of the structure and properties of glasses, where subtle differences in structure appear due to differences in the temperature and pressure conditions at which they were synthesized.

9.
BMC Biol ; 21(1): 93, 2023 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-37095510

RESUMEN

BACKGROUND: RNA 5-methyluridine (m5U) modifications are obtained by methylation at the C5 position of uridine catalyzed by pyrimidine methylation transferase, which is related to the development of human diseases. Accurate identification of m5U modification sites from RNA sequences can contribute to the understanding of their biological functions and the pathogenesis of related diseases. Compared to traditional experimental methods, computational methods developed based on machine learning with ease of use can identify modification sites from RNA sequences in an efficient and time-saving manner. Despite the good performance of these computational methods, there are some drawbacks and limitations. RESULTS: In this study, we have developed a novel predictor, m5U-SVM, based on multi-view features and machine learning algorithms to construct predictive models for identifying m5U modification sites from RNA sequences. In this method, we used four traditional physicochemical features and distributed representation features. The optimized multi-view features were obtained from the four fused traditional physicochemical features by using the two-step LightGBM and IFS methods, and then the distributed representation features were fused with the optimized physicochemical features to obtain the new multi-view features. The best performing classifier, support vector machine, was identified by screening different machine learning algorithms. Compared with the results, the performance of the proposed model is better than that of the existing state-of-the-art tool. CONCLUSIONS: m5U-SVM provides an effective tool that successfully captures sequence-related attributes of modifications and can accurately predict m5U modification sites from RNA sequences. The identification of m5U modification sites helps to understand and delve into the related biological processes and functions.


Asunto(s)
ARN , Máquina de Vectores de Soporte , Humanos , Algoritmos , Metilación , Biología Computacional/métodos
10.
Plant Mol Biol ; 112(1-2): 33-45, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37014509

RESUMEN

The primary transcript structure provides critical insights into protein diversity, transcriptional modification, and functions. Cassava transcript structures are highly diverse because of alternative splicing (AS) events and high heterozygosity. To precisely determine and characterize transcript structures, fully sequencing cloned transcripts is the most reliable method. However, cassava annotations were mainly determined according to fragmentation-based sequencing analyses (e.g., EST and short-read RNA-seq). In this study, we sequenced the cassava full-length cDNA library, which included rare transcripts. We obtained 8,628 non-redundant fully sequenced transcripts and detected 615 unannotated AS events and 421 unannotated loci. The different protein sequences resulting from the unannotated AS events tended to have diverse functional domains, implying that unannotated AS contributes to the truncation of functional domains. The unannotated loci tended to be derived from orphan genes, implying that the loci may be associated with cassava-specific traits. Unexpectedly, individual cassava transcripts were more likely to have multiple AS events than Arabidopsis transcripts, suggestive of the regulated interactions between cassava splicing-related complexes. We also observed that the unannotated loci and/or AS events were commonly in regions with abundant single nucleotide variations, insertions-deletions, and heterozygous sequences. These findings reflect the utility of completely sequenced FLcDNA clones for overcoming cassava-specific annotation-related problems to elucidate transcript structures. Our work provides researchers with transcript structural details that are useful for annotating highly diverse and unique transcripts and alternative splicing events.


Asunto(s)
Empalme Alternativo , Manihot , Empalme Alternativo/genética , Manihot/genética , Manihot/metabolismo , Nucleótidos , Biblioteca de Genes , Secuencia de Bases
11.
Brief Bioinform ; 22(5)2021 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-33454758

RESUMEN

Over the past decades, learning to rank (LTR) algorithms have been gradually applied to bioinformatics. Such methods have shown significant advantages in multiple research tasks in this field. Therefore, it is necessary to summarize and discuss the application of these algorithms so that these algorithms are convenient and contribute to bioinformatics. In this paper, the characteristics of LTR algorithms and their strengths over other types of algorithms are analyzed based on the application of multiple perspectives in bioinformatics. Finally, the paper further discusses the shortcomings of the LTR algorithms, the methods and means to better use the algorithms and some open problems that currently exist.


Asunto(s)
Algoritmos , Biología Computacional/métodos , ADN/química , Drogas en Investigación/farmacología , Proteínas/química , Programas Informáticos , Secuencia de Aminoácidos , ADN/genética , ADN/metabolismo , Descubrimiento de Drogas , Drogas en Investigación/síntesis química , Humanos , Dominios Proteicos , Estructura Secundaria de Proteína , Proteínas/genética , Proteínas/metabolismo , Homología de Secuencia de Aminoácido
12.
Brief Bioinform ; 22(5)2021 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-33822870

RESUMEN

MOTIVATION: Peptides have recently emerged as promising therapeutic agents against various diseases. For both research and safety regulation purposes, it is of high importance to develop computational methods to accurately predict the potential toxicity of peptides within the vast number of candidate peptides. RESULTS: In this study, we proposed ATSE, a peptide toxicity predictor by exploiting structural and evolutionary information based on graph neural networks and attention mechanism. More specifically, it consists of four modules: (i) a sequence processing module for converting peptide sequences to molecular graphs and evolutionary profiles, (ii) a feature extraction module designed to learn discriminative features from graph structural information and evolutionary information, (iii) an attention module employed to optimize the features and (iv) an output module determining a peptide as toxic or non-toxic, using optimized features from the attention module. CONCLUSION: Comparative studies demonstrate that the proposed ATSE significantly outperforms all other competing methods. We found that structural information is complementary to the evolutionary information, effectively improving the predictive performance. Importantly, the data-driven features learned by ATSE can be interpreted and visualized, providing additional information for further analysis. Moreover, we present a user-friendly online computational platform that implements the proposed ATSE, which is now available at http://server.malab.cn/ATSE. We expect that it can be a powerful and useful tool for researchers of interest.


Asunto(s)
Biología Computacional/métodos , Aprendizaje Automático , Redes Neurales de la Computación , Péptidos/toxicidad , Programas Informáticos , Bases de Datos de Proteínas , Conjuntos de Datos como Asunto , Evolución Molecular , Humanos , Péptidos/química
13.
Bioinformatics ; 38(7): 1964-1971, 2022 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-35134828

RESUMEN

MOTIVATION: Drug-target interaction prediction plays an important role in new drug discovery and drug repurposing. Binding affinity indicates the strength of drug-target interactions. Predicting drug-target binding affinity is expected to provide promising candidates for biologists, which can effectively reduce the workload of wet laboratory experiments and speed up the entire process of drug research. Given that, numerous new proteins are sequenced and compounds are synthesized, several improved computational methods have been proposed for such predictions, but there are still some challenges. (i) Many methods only discuss and implement one application scenario, they focus on drug repurposing and ignore the discovery of new drugs and targets. (ii) Many methods do not consider the priority order of proteins (or drugs) related to each target drug (or protein). Therefore, it is necessary to develop a comprehensive method that can be used in multiple scenarios and focuses on candidate order. RESULTS: In this study, we propose a method called NerLTR-DTA that uses the neighbor relationship of similarity and sharing to extract features, and applies a ranking framework with regression attributes to predict affinity values and priority order of query drug (or query target) and its related proteins (or compounds). It is worth noting that using the characteristics of learning to rank to set different queries can smartly realize the multi-scenario application of the method, including the discovery of new drugs and new targets. Experimental results on two commonly used datasets show that NerLTR-DTA outperforms some state-of-the-art competing methods. NerLTR-DTA achieves excellent performance in all application scenarios mentioned in this study, and the rm(test)2 values guarantee such excellent performance is not obtained by chance. Moreover, it can be concluded that NerLTR-DTA can provide accurate ranking lists for the relevant results of most queries through the statistics of the association relationship of each query drug (or query protein). In general, NerLTR-DTA is a powerful tool for predicting drug-target associations and can contribute to new drug discovery and drug repurposing. AVAILABILITY AND IMPLEMENTATION: The proposed method is implemented in Python and Java. Source codes and datasets are available at https://github.com/RUXIAOQING964914140/NerLTR-DTA.


Asunto(s)
Algoritmos , Programas Informáticos , Desarrollo de Medicamentos/métodos , Descubrimiento de Drogas/métodos , Reposicionamiento de Medicamentos , Proteínas/química
14.
Bioinformatics ; 38(6): 1514-1524, 2022 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-34999757

RESUMEN

MOTIVATION: Recently, peptides have emerged as a promising class of pharmaceuticals for various diseases treatment poised between traditional small molecule drugs and therapeutic proteins. However, one of the key bottlenecks preventing them from therapeutic peptides is their toxicity toward human cells, and few available algorithms for predicting toxicity are specially designed for short-length peptides. RESULTS: We present ToxIBTL, a novel deep learning framework by utilizing the information bottleneck principle and transfer learning to predict the toxicity of peptides as well as proteins. Specifically, we use evolutionary information and physicochemical properties of peptide sequences and integrate the information bottleneck principle into a feature representation learning scheme, by which relevant information is retained and the redundant information is minimized in the obtained features. Moreover, transfer learning is introduced to transfer the common knowledge contained in proteins to peptides, which aims to improve the feature representation capability. Extensive experimental results demonstrate that ToxIBTL not only achieves a higher prediction performance than state-of-the-art methods on the peptide dataset, but also has a competitive performance on the protein dataset. Furthermore, a user-friendly online web server is established as the implementation of the proposed ToxIBTL. AVAILABILITY AND IMPLEMENTATION: The proposed ToxIBTL and data can be freely accessible at http://server.wei-group.net/ToxIBTL. Our source code is available at https://github.com/WLYLab/ToxIBTL. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Aprendizaje Automático , Péptidos , Humanos , Proteínas , Programas Informáticos , Algoritmos
15.
Int Immunol ; 34(5): 277-289, 2022 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-35094065

RESUMEN

Effective tumor immunotherapy requires physical contact of T cells with cancer cells. However, tumors often constitute a specialized microenvironment that excludes T cells from the vicinity of cancer cells, and its underlying mechanisms are still poorly understood. DOCK2 is a Rac activator critical for migration and activation of lymphocytes. We herein show that cancer-derived cholesterol sulfate (CS), a lipid product of the sulfotransferase SULT2B1b, acts as a DOCK2 inhibitor and prevents tumor infiltration by effector T cells. Using clinical samples, we found that CS was abundantly produced in certain types of human cancers such as colon cancers. Functionally, CS-producing cancer cells exhibited resistance to cancer-specific T-cell transfer and immune checkpoint blockade. Although SULT2B1b is known to sulfate oxysterols and inactivate their tumor-promoting activity, the expression levels of cholesterol hydroxylases, which mediate oxysterol production, are low in SULT2B1b-expressing cancers. Therefore, SULT2B1b inhibition could be a therapeutic strategy to disrupt tumor immune evasion in oxysterol-non-producing cancers. Thus, our findings define a previously unknown mechanism for tumor immune evasion and provide a novel insight into the development of effective immunotherapies.


Asunto(s)
Neoplasias , Oxiesteroles , Ésteres del Colesterol/metabolismo , Humanos , Inmunoterapia , Linfocitos T/metabolismo , Microambiente Tumoral
16.
Phys Chem Chem Phys ; 25(27): 17978-17986, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37377109

RESUMEN

The atomic descriptors used in machine learning to predict forces are often high dimensional. In general, by retrieving a significant amount of structural information from these descriptors, accurate force predictions can be achieved. On the other hand, to acquire higher robustness for transferability without overfitting, sufficient reduction of descriptors should be necessary. In this study, we propose a method to automatically determine hyperparameters in the atomic descriptors, aiming to obtain accurate machine learning forces while using a small number of descriptors. Our method focuses on identifying an appropriate threshold cut-off for the variance value of the descriptor components. To demonstrate the effectiveness of our method, we apply it to crystalline, liquid, and amorphous structures in SiO2, SiGe, and Si systems. By using both conventional two-body descriptors and our introduced split-type three-body descriptors, we demonstrate that our method can provide machine learning forces that enable efficient and robust molecular dynamics simulations.

17.
J Biomed Inform ; 137: 104264, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36462599

RESUMEN

The demand for the privacy-preserving survival analysis of medical data integrated from multiple institutions or countries has been increased. However, sharing the original medical data is difficult because of privacy concerns, and even if it could be achieved, we have to pay huge costs for cross-institutional or cross-border communications. To tackle these difficulties of privacy-preserving survival analysis on multiple parties, this study proposes a novel data collaboration Cox proportional hazards (DC-COX) model based on a data collaboration framework for horizontally and vertically partitioned data. By integrating dimensionality-reduced intermediate representations instead of the original data, DC-COX obtains a privacy-preserving survival analysis without iterative cross-institutional communications or huge computational costs. DC-COX enables each local party to obtain an approximation of the maximum likelihood model parameter, the corresponding statistic, such as the p-value, and survival curves for subgroups. Based on a bootstrap technique, we introduce a dimensionality reduction method to improve the efficiency of DC-COX. Numerical experiments demonstrate that DC-COX can compute a model parameter and the corresponding statistics with higher performance than the local party analysis. Particularly, DC-COX demonstrates outstanding performance in essential feature selection based on the p-value compared with the existing methods including the federated learning-based method.


Asunto(s)
Comunicación , Privacidad , Modelos de Riesgos Proporcionales , Análisis de Supervivencia
18.
Biochem Biophys Res Commun ; 609: 183-188, 2022 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-35452959

RESUMEN

Effective cancer immunotherapy requires physical contact of T cells with cancer cells. However, tumors often constitute special microenvironments that exclude T cells and resist immunotherapy. Cholesterol sulfate (CS) is a product of sulfotransferase SULT2B1b and acts as an endogenous inhibitor of DOCK2, a Rac activator essential for migration and activation of lymphocytes. We have recently shown that cancer-derived CS prevents tumor infiltration by effector T cells. Therefore, SULT2B1b may be a therapeutic target to dampen CS-mediated immune evasion. Here, we identified 3ß-hydroxy-5-cholenoic acid (3ß-OH-5-Chln) as a cell-active inhibitor of SULT2B1b. 3ß-OH-5-Chln inhibited the cholesterol sulfotransferase activity of SULT2B1b in vitro and suppressed CS production from cancer cells expressing SULT2B1b. In vivo administration of 3ß-OH-5-Chln locally reduced CS level in murine CS-producing tumors and increased infiltration of CD8+ T cells. When combined with immune checkpoint blockade or antigen-specific T cell transfer, 3ß-OH-5-Chln suppressed the growth of CS-producing tumors. These results demonstrate that pharmacological inhibition of SULT2B1b can promote antitumor immunity through suppressing CS-mediated T cell exclusion.


Asunto(s)
Linfocitos T CD8-positivos , Neoplasias , Animales , Ésteres del Colesterol , Proteínas Activadoras de GTPasa , Factores de Intercambio de Guanina Nucleótido , Ratones , Neoplasias/tratamiento farmacológico , Sulfotransferasas , Microambiente Tumoral
19.
Int Immunol ; 33(3): 149-160, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-32986079

RESUMEN

Innate lymphoid cells (ILCs) are a family of developmentally related leukocytes that rapidly secrete polarized sets of cytokines to combat infection and promote tissue repair at mucosal barriers. Among them, group 3 ILCs (ILC3s) play an important role in maintenance of the gut homeostasis by producing IL-22, and their development and function critically depend on the transcription factor RORγt. Although recent evidence indicates that RORγt+ ILC3s are reduced in the gut in the absence of the Cdc42 activator DOCK8 (dedicator of cytokinesis 8), the underlying mechanism remains unclear. We found that genetic deletion of Dock8 in RORγt+-lineage cells markedly reduced ILC3s in the lamina propria of the small intestine. By analyzing BrdU incorporation, it was revealed that DOCK8 deficiency did not affect the cell proliferation. Furthermore, when lineage marker-negative (Lin-) α4ß7+ CD127+ RORγt- fetal liver cells were cultured with OP9 stromal cells in the presence of stem cell factor (SCF) and IL-7 in vitro, RORγt+ ILC3s normally developed irrespective of DOCK8 expression. However, DOCK8-deficient ILC3s exhibited a severe defect in survival of ILC3s under the condition with or without IL-7. Similar defects were observed when we analyzed Dock8VAGR mice having mutations in the catalytic center of DOCK8, thereby failing to activate Cdc42. Thus, DOCK8 acts in cell-autonomous manner to control survival of ILC3s in the gut through Cdc42 activation.


Asunto(s)
Factores de Intercambio de Guanina Nucleótido/metabolismo , Mucosa Intestinal/citología , Linfocitos/metabolismo , Proteína de Unión al GTP cdc42/metabolismo , Animales , Dominio Catalítico/genética , Línea Celular , Proliferación Celular/genética , Supervivencia Celular/genética , Citocinas/metabolismo , Activación Enzimática/inmunología , Factores de Intercambio de Guanina Nucleótido/genética , Células HEK293 , Humanos , Interleucina-7/metabolismo , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Factor de Células Madre/metabolismo
20.
J Biomed Inform ; 128: 104049, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35283266

RESUMEN

Renal cell carcinoma (RCC) is one of the deadliest cancers and mainly consists of three subtypes: kidney clear cell carcinoma (KIRC), kidney papillary cell carcinoma (KIRP), and kidney chromophobe (KICH). Gene signature identification plays an important role in the precise classification of RCC subtypes and personalized treatment. However, most of the existing gene selection methods focus on statically selecting the same informative genes for each subtype, and fail to consider the heterogeneity of patients which causes pattern differences in each subtype. In this work, to explore different informative gene subsets for each subtype, we propose a novel gene selection method, named sequential reinforcement active feature learning (SRAFL), which dynamically acquire the different genes in each sample to identify the different gene signatures for each subtype. The proposed SRAFL method combines the cancer subtype classifier with the reinforcement learning (RL) agent, which sequentially select the active genes in each sample from three mixed RCC subtypes in a cost-sensitive manner. Moreover, the module-based gene filtering is run before gene selection to filter the redundant genes. We mainly evaluate the proposed SRAFL method based on mRNA and long non-coding RNA (lncRNA) expression profiles of RCC datasets from The Cancer Genome Atlas (TCGA). The experimental results demonstrate that the proposed method can automatically identify different gene signatures for different subtypes to accurately classify RCC subtypes. More importantly, we here for the first time show the proposed SRAFL method can consider the heterogeneity of samples to select different gene signatures for different RCC subtypes, which shows more potential for the precision-based RCC care in the future.


Asunto(s)
Carcinoma de Células Renales , Neoplasias Renales , Carcinoma de Células Renales/diagnóstico , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/metabolismo , Genoma , Humanos , Neoplasias Renales/diagnóstico , Neoplasias Renales/genética , Neoplasias Renales/metabolismo , ARN Mensajero
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