Updates on the biomarker status of the human equilibrative nucleoside transporter-1 and molecular mechanisms influencing its expression and activity in the uptake and cytotoxicity

Pancreatology ◽  
2021 ◽  
Vol 21 ◽  
pp. S71
Author(s):  
G. Mantini ◽  
F. Papini ◽  
M. Capula ◽  
O. Randazzo ◽  
A. Gregori ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Nucleoside Transporter ◽  
Equilibrative Nucleoside Transporter ◽  
Expression And Activity

scholarly journals HIF-1–dependent repression of equilibrative nucleoside transporter (ENT) in hypoxia

2005 ◽  
Vol 202 (11) ◽  
pp. 1493-1505 ◽  
Author(s):  
Holger K. Eltzschig ◽  
Parween Abdulla ◽  
Edgar Hoffman ◽  
Kathryn E. Hamilton ◽  
Dionne Daniels ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Molecular Mechanisms ◽  
Hypoxia Inducible Factor ◽  
Nucleoside Transporter ◽  
In Vivo Models ◽  
Equilibrative Nucleoside Transporter ◽  
Hypoxia Inducible Factor 1 ◽  
And Function

Extracellular adenosine (Ado) has been implicated as central signaling molecule during conditions of limited oxygen availability (hypoxia), regulating physiologic outcomes as diverse as vascular leak, leukocyte activation, and accumulation. Presently, the molecular mechanisms that elevate extracellular Ado during hypoxia are unclear. In the present study, we pursued the hypothesis that diminished uptake of Ado effectively enhances extracellular Ado signaling. Initial studies indicated that the half-life of Ado was increased by as much as fivefold after exposure of endothelia to hypoxia. Examination of expressional levels of the equilibrative nucleoside transporter (ENT)1 and ENT2 revealed a transcriptionally dependent decrease in mRNA, protein, and function in endothelia and epithelia. Examination of the ENT1 promoter identified a hypoxia inducible factor 1 (HIF-1)–dependent repression of ENT1 during hypoxia. Using in vitro and in vivo models of Ado signaling, we revealed that decreased Ado uptake promotes vascular barrier and dampens neutrophil tissue accumulation during hypoxia. Moreover, epithelial Hif1α mutant animals displayed increased epithelial ENT1 expression. Together, these results identify transcriptional repression of ENT as an innate mechanism to elevate extracellular Ado during hypoxia.

scholarly journals “Open Sesame?”: Biomarker Status of the Human Equilibrative Nucleoside Transporter-1 and Molecular Mechanisms Influencing its Expression and Activity in the Uptake and Cytotoxicity of Gemcitabine in Pancreatic Cancer

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3206
Author(s):  
Ornella Randazzo ◽  
Filippo Papini ◽  
Giulia Mantini ◽  
Alessandro Gregori ◽  
Barbara Parrino ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Ductal Adenocarcinoma ◽  
Rapid Progression ◽  
Nucleoside Transporter ◽  
Equilibrative Nucleoside Transporter ◽  
Multimodal Analysis ◽  
Predictive Role ◽  
Aggressive Tumor ◽  
Disease Free ◽  
Free Status

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive tumor characterized by early invasiveness, rapid progression and resistance to treatment. For more than twenty years, gemcitabine has been the main therapy for PDAC both in the palliative and adjuvant setting. After the introduction of FOLFIRINOX as an upfront treatment for metastatic disease, gemcitabine is still commonly used in combination with nab-paclitaxel as an alternative first-line regimen, as well as a monotherapy in elderly patients unfit for combination chemotherapy. As a hydrophilic nucleoside analogue, gemcitabine requires nucleoside transporters to permeate the plasma membrane, and a major role in the uptake of this drug is played by human equilibrative nucleoside transporter 1 (hENT-1). Several studies have proposed hENT-1 as a biomarker for gemcitabine efficacy in PDAC. A recent comprehensive multimodal analysis of hENT-1 status evaluated its predictive role by both immunohistochemistry (with five different antibodies), and quantitative-PCR, supporting the use of the 10D7G2 antibody. High hENT-1 levels observed with this antibody were associated with prolonged disease-free status and overall-survival in patients receiving gemcitabine adjuvant chemotherapy. This commentary aims to critically discuss this analysis and lists molecular factors influencing hENT-1 expression. Improved knowledge on these factors should help the identification of subgroups of patients who may benefit from specific therapies and overcome the limitations of traditional biomarker studies.

The Anti-Proliferative Activity of Anisosciadone: A New Guaiane Sesquiterpene from Anisosciadium lanatum

2019 ◽  
Vol 19 (9) ◽  
pp. 1114-1119 ◽  
Author(s):  
Ahmed A. Mahmoud ◽  
Wael M. El-Sayed
Keyword(s):  
Anticancer Agents ◽  
Antiproliferative Activity ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Chemical Constituents ◽  
Spectroscopic Techniques ◽  
Significant Activity ◽  
Caspase 9 ◽  
P53 Expression ◽  
Expression And Activity

Background: The increase in cancer rate and the development of resistant tumors require a continuous search for new anticancer agents. Aims: This study aimed to analyze and identify the chemical constituents of Anisosciadium lanatum, and to investigate the antiproliferative activity of the identified constituents against various human cell lines (HepG2, MCF7, HT29, A549, and PC3) along with the possible molecular mechanisms involved. Methods: The structure of the isolated compounds was determined by spectroscopic techniques including HRFABMS, GC-MS, IR, and 400 MHz 1D and 2D NMR analyses (1H, 13C NMR, DEPT, 1H-1H COSY, HMQC, HMBC and NOESY). The antiproliferative activity and IC50 value of the isolated compounds were measured and compared to doxorubicin. Results: A new guaiane sesquiterpene containing a rare epoxide structural element, 10β,11β−epoxy−1α,4β,5β,7αΗ- guaiane-9-one, anisosciadone (1), and stigmasterol (2) have been isolated from the plant. Anisosciadone (1) showed a significant antiproliferative activity against liver, colon, and lung cells only, while stigmasterol (2) had a significant activity against liver, colon, and breast cells. Both 1 and 2 caused no cytotoxicity to normal fibroblasts. Anisosciadone elevated the expression and activity of Caspase 3 as well as p53 expression without affecting Caspase 9 in HepG2 cells. It also caused ~ 50% downregulation in cdk1 expression. Conclusion: Taken together, anisosciadone was specific in action against cancer cells and induced apoptosis in liver cells. It also has a unique feature by elevating the expression and activity of Caspase 3 without affecting the initiator Caspase 9. Therefore, anisosciadone deserves more investigation as a targeted therapy for cancer.

Contribution of equilibrative nucleoside transporter (ENT) 2 to fluorouracil transport in rat placental trophoblast cells

2017 ◽  
Vol 32 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Akinori Takagi ◽  
Tomohiro Nishimura ◽  
Tomoya Akashi ◽  
Masatoshi Tomi ◽  
Emi Nakashima
Keyword(s):  
Nucleoside Transporter ◽  
Trophoblast Cells ◽  
Equilibrative Nucleoside Transporter

Nucleoside Transporter-guided Cytarabine Conjugated Liposomes for Intracellular Methotrexate Delivery and Cooperative Choriocarcinoma Therapy

2021 ◽  
Author(s):  
Weidong Fei ◽  
Yunchun Zhao ◽  
Xiaodong Wu ◽  
Dongli Sun ◽  
Yao Yao ◽  
...  
Keyword(s):  
Targeted Delivery ◽  
Rational Design ◽  
High Efficiency ◽  
Nucleoside Transporter ◽  
Childbearing Age ◽  
Equilibrative Nucleoside Transporter ◽  
Choriocarcinoma Cells ◽  
Tumor Accumulation ◽  
Novel Strategy ◽  
Distribution Studies

Abstract The gestational trophoblastic tumor seriously endangers child productive needs and the health of women in childbearing age. Nanodrug-based therapy mediated by transporters provides novel strategy for the treatment of trophoblastic tumors. Focus on the overexpressed human equilibrative nucleoside transporter 1 (ENT1) on the membrane of choriocarcinoma cells (JEG-3), the cytarabine (Cy, a substrate of ENT1) grafted liposome (Cy-Lipo) was introduced for targeted delivery of methotrexate (Cy-Lipo@MTX) for choriocarcinoma therapy in this study. The ENT1 has high affinity for Cy-Lipo and can mediate the endocytosis of the designed nanovehicles into JEG-3 cells. The ENT1 protein maintains its transporting function through circulation and regeneration during endocytosis. Therefore, Cy-Lipo-based formulations achieved high tumor accumulation and retention in pharmacokinetic and distribution studies. More importantly, the designed Cy-lipid conjugation exhibited a synergistic therapeutic effect on choriocarcinoma. Finally, Cy-Lipo@MTX exerts an extremely powerful anti-choriocarcinoma effect with fewer side effects. This study suggests that the overexpressed ENT1 on choriocarcinoma cells holds a great potential to be a high-efficiency target for the rational design of active targeting nanotherapeutics.

scholarly journals The role of the equilibrative nucleoside transporter 1 on tissue and fetal distribution of ribavirin in the mouse

2016 ◽  
Vol 37 (6) ◽  
pp. 336-344 ◽  
Author(s):  
Christopher J. Endres ◽  
Aaron M. Moss ◽  
Kazuya Ishida ◽  
Rajgopal Govindarajan ◽  
Jashvant D. Unadkat
Keyword(s):  
Nucleoside Transporter ◽  
Equilibrative Nucleoside Transporter
Sign in / Sign up

Export Citation Format

Share Document