scholarly journals Chemical genetics strategy to profile kinase target engagement reveals role of FES in neutrophil phagocytosis via SYK activation

2019 ◽  
Author(s):  
Tom van der Wel ◽  
Riet Hilhorst ◽  
Hans den Dulk ◽  
Tim van den Hooven ◽  
Nienke M. Prins ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Chemical Genetics ◽  
Binding Pocket ◽  
Myeloid Differentiation ◽  
Target Engagement ◽  
Syk Kinase ◽  
Promising Therapeutic Target ◽  
Single Oxygen Atom ◽  
Single Oxygen

AbstractChemical tools and methods that report on target engagement of endogenously expressed protein kinases by small molecules in human cells are highly desirable. Here, we describe a chemical genetics strategy that allows the study of non-receptor tyrosine kinase FES, a promising therapeutic target for cancer and immune disorders. Precise gene editing was used in combination with a rationally designed, complementary fluorescent probe to visualize endogenous FES kinase in HL-60 cells. We replaced a single oxygen atom by a sulphur in a serine residue at the DFG-1 position of the ATP-binding pocket in an endogenously expressed kinase, thereby sensitizing the engineered protein towards covalent labeling and inactivation by a fluorescent probe. The temporal control offered by this strategy allows acute inactivation of FES activity both during myeloid differentiation and in terminally differentiated neutrophils. Our results show that FES activity is dispensable for differentiation of HL-60 cells towards macrophages. Instead, FES plays a key role in neutrophil phagocytosis by activation of SYK kinase, a central regulator of immune function in neutrophils. This strategy holds promise as a target validation method for kinases.

scholarly journals How Does Single Oxygen Atom Addition Affect the Properties of an Fe−Nitrile Hydratase Analogue? The Compensatory Role of the Unmodified Thiolate

2006 ◽  
Vol 128 (34) ◽  
pp. 11211-11221 ◽  
Author(s):  
Priscilla Lugo-Mas ◽  
Abhishek Dey ◽  
Liang Xu ◽  
Steven D. Davin ◽  
Jason Benedict ◽  
...  
Keyword(s):  
Oxygen Atom ◽  
Nitrile Hydratase ◽  
Single Oxygen Atom ◽  
Single Oxygen

scholarly journals Chemical genetics strategy to profile kinase target engagement reveals role of FES in neutrophil phagocytosis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Tom van der Wel ◽  
Riet Hilhorst ◽  
Hans den Dulk ◽  
Tim van den Hooven ◽  
Nienke M. Prins ◽  
...  
Keyword(s):  
Chemical Genetics ◽  
Target Engagement

MiRNA-145 and Its Direct Downstream Targets in Digestive System Cancers: A Promising Therapeutic Target

2020 ◽  
Vol 26 ◽  
Author(s):  
Yini Ma ◽  
Xiu Cao ◽  
Guojuan Shi ◽  
Tianlu Shi
Keyword(s):  
Digestive System ◽  
Target Genes ◽  
Malignant Neoplasm ◽  
Vital Role ◽  
Diagnostic Biomarkers ◽  
Cellular Processes ◽  
Promising Therapeutic Target ◽  
Direct Target ◽  
Potential Strategy

: MicroRNAs (miRNAs) play a vital role in the onset and development of many diseases, including cancers. Emerging evidence shows that numerous miRNAs have the potential to be used as diagnostic biomarkers for cancers, and miRNA-based therapy may be a promising therapy for the treatment of malignant neoplasm. MicroRNA-145 (miR-145) has been considered to play certain roles in various cellular processes, such as proliferation, differentiation and apoptosis, via modulating expression of direct target genes. Recent reports show that miR-145 participates in the progression of digestive system cancers, and plays crucial and novel roles for cancer treatment. In this review, we summarize the recent knowledge concerning the function of miR-145 and its direct targets in digestive system cancers. We discuss the potential role of miR-145 as valuable biomarkers for digestive system cancers and how miR-145 regulates these digestive system cancers via different targets to explore the potential strategy of targeting miR-145.

Chemical Genetics Reveals a Role of Squalene Synthase in TGFβ Signaling and Cardiomyogenesis

2021 ◽  
Author(s):  
Yasushi Takemoto ◽  
Shin Kadota ◽  
Itsunari Minami ◽  
Shinya Otsuka ◽  
Satoshi Okuda ◽  
...  
Keyword(s):  
Chemical Genetics ◽  
Squalene Synthase ◽  
Tgfβ Signaling

scholarly journals Role of Sialyl-O-Acetyltransferase CASD1 on GD2 Ganglioside O-Acetylation in Breast Cancer Cells

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1468
Author(s):  
Sumeyye Cavdarli ◽  
Larissa Schröter ◽  
Malena Albers ◽  
Anna-Maria Baumann ◽  
Dorothée Vicogne ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Cancer Cell Line ◽  
Wild Type ◽  
Cellular Models ◽  
Promising Therapeutic Target ◽  
Plasmid Transfection ◽  
Ganglioside Species

The O-acetylated form of GD2, almost exclusively expressed in cancerous tissues, is considered to be a promising therapeutic target for neuroectoderm-derived tumors, especially for breast cancer. Our recent data have shown that 9-O-acetylated GD2 (9-OAcGD2) is the major O-acetylated ganglioside species in breast cancer cells. In 2015, Baumann et al. proposed that Cas 1 domain containing 1 (CASD1), which is the only known human sialyl-O-acetyltransferase, plays a role in GD3 O-acetylation. However, the mechanisms of ganglioside O-acetylation remain poorly understood. The aim of this study was to determine the involvement of CASD1 in GD2 O-acetylation in breast cancer. The role of CASD1 in OAcGD2 synthesis was first demonstrated using wild type CHO and CHOΔCasd1 cells as cellular models. Overexpression using plasmid transfection and siRNA strategies was used to modulate CASD1 expression in SUM159PT breast cancer cell line. Our results showed that OAcGD2 expression was reduced in SUM159PT that was transiently depleted for CASD1 expression. Additionally, OAcGD2 expression was increased in SUM159PT cells transiently overexpressing CASD1. The modulation of CASD1 expression using transient transfection strategies provided interesting insights into the role of CASD1 in OAcGD2 and OAcGD3 biosynthesis, and it highlights the importance of further studies on O-acetylation mechanisms.

scholarly journals The Relevance of the SH2 Domain for c-Src Functionality in Triple-Negative Breast Cancer Cells

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 462
Author(s):  
Víctor Mayoral-Varo ◽  
María Pilar Sánchez-Bailón ◽  
Annarica Calcabrini ◽  
Marta García-Hernández ◽  
Valerio Frezza ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Sh2 Domain ◽  
Model Systems ◽  
System A ◽  
Promising Therapeutic Target ◽  
Relevant Role ◽  
Inactivating Mutation

The role of Src family kinases (SFKs) in human tumors has been always associated with tyrosine kinase activity and much less attention has been given to the SH2 and SH3 adapter domains. Here, we studied the role of the c-Src-SH2 domain in triple-negative breast cancer (TNBC). To this end, SUM159PT and MDA-MB-231 human cell lines were employed as model systems. These cells conditionally expressed, under tetracycline control (Tet-On system), a c-Src variant with point-inactivating mutation of the SH2 adapter domain (R175L). The expression of this mutant reduced the self-renewal capability of the enriched population of breast cancer stem cells (BCSCs), demonstrating the importance of the SH2 adapter domain of c-Src in the mammary gland carcinogenesis. In addition, the analysis of anchorage-independent growth, proliferation, migration, and invasiveness, all processes associated with tumorigenesis, showed that the SH2 domain of c-Src plays a very relevant role in their regulation. Furthermore, the transfection of two different aptamers directed to SH2-c-Src in both SUM159PT and MDA-MB-231 cells induced inhibition of their proliferation, migration, and invasiveness, strengthening the hypothesis that this domain is highly involved in TNBC tumorigenesis. Therefore, the SH2 domain of c-Src could be a promising therapeutic target and combined treatments with inhibitors of c-Src kinase enzymatic activity may represent a new therapeutic strategy for patients with TNBC, whose prognosis is currently very negative.

scholarly journals The Role of the Histone Methyltransferase EZH2 in Liver Inflammation and Fibrosis in STAM NASH Mice

Biology ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 93 ◽  
Author(s):  
Seul Lee ◽  
Dong-Cheol Woo ◽  
Jeeheon Kang ◽  
Moonjin Ra ◽  
Ki Hyun Kim ◽  
...  
Keyword(s):  
Liver Disease ◽  
Epigenetic Modification ◽  
Treatment Options ◽  
Histone Methyltransferase ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Steatohepatitis ◽  
Promising Therapeutic Target ◽  
Alcoholic Fatty Liver Disease ◽  
Potential Therapeutics

Non-alcoholic fatty liver disease (NAFLD) is a leading form of chronic liver disease, with few biomarkers and treatment options currently available. Non-alcoholic steatohepatitis (NASH), a progressive disease of NAFLD, may lead to fibrosis, cirrhosis, and hepatocellular carcinoma. Epigenetic modification can contribute to the progression of NAFLD causing non-alcoholic steatohepatitis (NASH), in which the exact role of epigenetics remains poorly understood. To identify potential therapeutics for NASH, we tested small-molecule inhibitors of the epigenetic target histone methyltransferase EZH2, Tazemetostat (EPZ-6438), and UNC1999 in STAM NASH mice. The results demonstrate that treatment with EZH2 inhibitors decreased serum TNF-alpha in NASH. In this study, we investigated that inhibition of EZH2 reduced mRNA expression of inflammatory cytokines and fibrosis markers in NASH mice. In conclusion, these results suggest that EZH2 may present a promising therapeutic target in the treatment of NASH.

scholarly journals Identification of Tyr residues that enhance folate substrate binding and constrain oscillation of the proton-coupled folate transporter (PCFT-SLC46A1)

2015 ◽  
Vol 308 (8) ◽  
pp. C631-C641 ◽  
Author(s):  
Michele Visentin ◽  
Ersin Selcuk Unal ◽  
Mitra Najmi ◽  
Andras Fiser ◽  
Rongbao Zhao ◽  
...  
Keyword(s):  
Choroid Plexus ◽  
Rate Constant ◽  
Binding Pocket ◽  
Wild Type ◽  
Efflux Rate ◽  
High Affinity ◽  
Extracellular Compartment ◽  
Efflux Rate Constant ◽  
Opposite Compartment

The proton-coupled folate transporter (PCFT) mediates intestinal folate absorption and transport of folates across the choroid plexus. This study focuses on the role of Tyr residues in PCFT function. The substituted Cys-accessibility method identified four Tyr residues (Y291, Y362, Y315, and Y414) that are accessible to the extracellular compartment; three of these (Y291, Y362, and Y315) are located within or near the folate binding pocket. When the Tyr residues were replaced with Cys or Ala, these mutants showed similar (up to 6-fold) increases in influx Vmax and Kt/ Ki for [3H]methotrexate and [3H]pemetrexed. When the Tyr residues were replaced with Phe, these changes were moderated or absent. When Y315A PCFT was used as representative of the mutants and [3H]pemetrexed as the transport substrate, this substitution did not increase the efflux rate constant. Furthermore, neither influx nor efflux mediated by Y315A PCFT was transstimulated by the presence of substrate in the opposite compartment; however, substantial bidirectional transstimulation of transport was mediated by wild-type PCFT. This resulted in a threefold greater efflux rate constant for cells that express wild-type PCFT than for cells that express Y315 PCFT under exchange conditions. These data suggest that these Tyr residues, possibly through their rigid side chains, secure the carrier in a high-affinity state for its folate substrates. However, this may be achieved at the expense of constraining the carrier's mobility, thereby decreasing the rate at which the protein oscillates between its conformational states. The Vmax generated by these Tyr mutants may be so rapid that further augmentation during transstimulation may not be possible.

An oligomer complementary to c-myc mRNA inhibits proliferation of HL-60 promyelocytic cells and induces differentiation

1988 ◽  
Vol 8 (2) ◽  
pp. 963-973
Author(s):  
J T Holt ◽  
R L Redner ◽  
A W Nienhuis
Keyword(s):  
Cell Growth ◽  
Protein Concentration ◽  
Myeloid Differentiation ◽  
Sequence Specificity ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Steady State Levels ◽  
Cell Growth And Differentiation ◽  
Antisense Oligomer

To study the role of a nuclear proto-oncogene in the regulation of cell growth and differentiation, we inhibited HL-60 c-myc expression with a complementary antisense oligomer. This oligomer was stable in culture and entered cells, forming an intracellular duplex. Incubation of cells with the anti-myc oligomer decreased the steady-state levels of c-myc protein by 50 to 80%, whereas a control oligomer did not significantly affect the c-myc protein concentration. Direct inhibition of c-myc expression with the anti-myc oligomer was associated with a decreased cell growth rate and an induction of myeloid differentiation. Related antisense oligomers with 2- to 12-base-pair mismatches with c-myc mRNA did not influence HL-60 cells. Thus, the effects of the antisense oligomer exhibited sequence specificity, and furthermore, these effects could be reversed by hybridization competition with another complementary oligomer. Antisense inhibition of a nuclear proto-oncogene apparently bypasses cell surface events in affecting cell proliferation and differentiation.

Electrochemical and Spectroscopic Study of Pyranine Fluorescent Probe: Role of Intermediates in Pyranine Oxidation

2011 ◽  
Vol 115 (20) ◽  
pp. 6661-6667 ◽  
Author(s):  
Gabriela Velásquez ◽  
M. Soledad Ureta-Zañartu ◽  
Camilo López-Alarcón ◽  
Alexis Aspée
Keyword(s):  
Spectroscopic Study ◽  
Fluorescent Probe
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