Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
1.
Exp Cell Res ; 319(14): 2244-53, 2013 Aug 15.
Article in English | MEDLINE | ID: mdl-23797032

ABSTRACT

The ChlR1 DNA helicase is mutated in Warsaw breakage syndrome characterized by developmental anomalies, chromosomal breakage, and sister chromatid cohesion defects. However, the mechanism by which ChlR1 preserves genomic integrity is largely unknown. Here, we describe the roles of ChlR1 in DNA replication recovery. We show that ChlR1 depletion renders human cells highly sensitive to cisplatin; an interstrand-crosslinking agent that causes stalled replication forks. ChlR1 depletion also causes accumulation of DNA damage in response to cisplatin, leading to a significant delay in resolution of DNA damage. We also report that ChlR1-depleted cells display defects in the repair of double-strand breaks induced by the I-PpoI endonuclease and bleomycin. Furthermore, we demonstrate that ChlR1-depeleted cells show significant delays in replication recovery after cisplatin treatment. Taken together, our results indicate that ChlR1 plays an important role in efficient DNA repair during DNA replication, which may facilitate efficient establishment of sister chromatid cohesion.


Subject(s)
DEAD-box RNA Helicases/metabolism , DNA Damage , DNA Helicases/metabolism , DNA Replication , Chromatids/drug effects , Chromatids/metabolism , Cisplatin/toxicity , Cross-Linking Reagents/toxicity , DEAD-box RNA Helicases/genetics , DNA End-Joining Repair , DNA Helicases/genetics , HEK293 Cells , HeLa Cells , Humans , RNA, Small Interfering
2.
ALTEX ; 40(4): 649-664, 2023.
Article in English | MEDLINE | ID: mdl-37422924

ABSTRACT

Lung cancer is a leading cause of death worldwide, with only a fraction of patients responding to immunotherapy. The correlation between increased T-cell infiltration and positive patient outcomes has motivated the search for therapeutics promoting T-cell infiltration. While transwell and spheroid platforms have been employed, these models lack flow and endothelial barriers, and cannot faithfully model T-cell adhesion, extravasation, and migration through 3D tissue. Presented here is a 3D chemotaxis assay, in a lung tumor-on-chip model with 3D endothelium (LToC-Endo), to address this need. The described assay consists of a HUVEC-derived vascular tubule cultured under rocking flow, through which T-cells are added; a collagenous stromal barrier, through which T-cells migrate; and a chemoattractant/tumor (HCC0827 or NCI-H520) compartment. Here, activated T-cells extravasate and migrate in response to gradients of rhCXCL11 and rhCXCL12. Adopting a T-cell activation protocol with a rest period enables proliferative burst prior to introducing T-cells into chips and enhances assay sensitivity. In addition, incorporating this rest recovers endothelial activation in response to rhCXCL12. As a final control, we show that blocking ICAM-1 interferes with T-cell adhesion and chemotaxis. This microphysiological system, which mimics in vivo stromal and vascular barriers, can be used to evaluate potentiation of immune chemotaxis into tumors while probing for vascular responses to potential therapeutics. Finally, we propose translational strategies by which this assay could be linked to preclinical and clinical models to support human dose prediction, personalized medicine, and the reduction, refinement, and replacement of animal models.


Subject(s)
Lung Neoplasms , Microphysiological Systems , Animals , Humans , Cells, Cultured , Endothelium, Vascular , Lung Neoplasms/drug therapy , Cell Movement
3.
Cancer Cell ; 36(1): 100-114.e25, 2019 07 08.
Article in English | MEDLINE | ID: mdl-31257072

ABSTRACT

Type I protein arginine methyltransferases (PRMTs) catalyze asymmetric dimethylation of arginines on proteins. Type I PRMTs and their substrates have been implicated in human cancers, suggesting inhibition of type I PRMTs may offer a therapeutic approach for oncology. The current report describes GSK3368715 (EPZ019997), a potent, reversible type I PRMT inhibitor with anti-tumor effects in human cancer models. Inhibition of PRMT5, the predominant type II PRMT, produces synergistic cancer cell growth inhibition when combined with GSK3368715. Interestingly, deletion of the methylthioadenosine phosphorylase gene (MTAP) results in accumulation of the metabolite 2-methylthioadenosine, an endogenous inhibitor of PRMT5, and correlates with sensitivity to GSK3368715 in cell lines. These data provide rationale to explore MTAP status as a biomarker strategy for patient selection.


Subject(s)
Antineoplastic Agents/pharmacology , Enzyme Inhibitors/pharmacology , Protein-Arginine N-Methyltransferases/antagonists & inhibitors , Purine-Nucleoside Phosphorylase/deficiency , Alternative Splicing , Antineoplastic Agents/chemistry , Biomarkers , Cell Line, Tumor , Drug Synergism , Enzyme Inhibitors/chemistry , Humans , Methylation , Models, Molecular , Molecular Conformation , Molecular Structure , Protein Binding , Protein-Arginine N-Methyltransferases/chemistry , Substrate Specificity
SELECTION OF CITATIONS
SEARCH DETAIL